I can't believe his SEVENTEEN year old son needs his daddy there for every bit of time during visitation.  We are talking about 3 vs 5 hours if I'm reading this right.  The kid is clearly old enough to be home alone.. should be well able to fend for himself for those hours.

I get that his dad is protective of his time with his son (kids in general I imagine).. since he gets relatively little of it.  BUT.. it's not like you chose to ask him to go apple picking on his son's visitation time.  You did not choose the venue or the timing.  and.. while I could see it being more difficult for a very young child to be managed.. a kid who is approaching adulthood?  come on.. he is being overly rigid.

I wonder if there is anything in that town that SS would be interested in doing.. perhaps with a friend? so he could come along.. and it would be less time not spending it with his son.

Your suggestion that he spend the balance of his weekend more one on one with his son.. is generous.. because I really don't think a kid that age is so needy that he can't accomodate his dad being gone for a few hours (5.. is a few to me).  

You aren't asking him to be left at home overnight.. he is old enough to take care of himself and to entertain himself.  I'm sure his mother feels free to make and attend events away from her children.. there is no reason why this can't be accomodated for a special occasion.. again.. not just some basic desire for you to spend adult time with him.. that could be scheduled any other time.

It's important for your DH to be part of YOUR life too. part of your social life... etc.. it's just as important as being there for his kids.. and I don't think missing a few hours with his son is in any way neglectful... and his son would certainly understand!

I'm going to make a few assumptions, and if I'm wrong, feel free to correct me and I'll adjust my advice.

I am assuming you met your DH when you were roughly 25 and he was roughly 55? So this milestone birthday would be someone turning 30? And if you're also about to turn 30, then that means there is less than a 10 year age gap between you and your SD.

So a couple of things. Let's start with the party. My guess is your DH falls into one of four camps. First, he feels old hanging out with a bunch of 20 and 30-somethings so he'd rather not be reminded that he's old. Second, he thinks these "milestone" type events are dumb because he has been there, done that and doesn't want to do it again. Third, he feels guilty about what happened with SD so he refuses to rock the boat with SS for fear of fallout. Fourth, he really thinks he needs to spend every waking moment with his 17 year old (and my guess is that he doesn't and has probably gone out for 5 hours at a time for things *he* wants or needs to do when SS is around).

In absolutely none of these scenarios is there anything you can explicitly do to make him come. You can share that you're saddened and disappointed. You can accept that he doesn't want to come and stop inviting him to all these things. You can sit at home with him instead of going out. You can leave the relationship. That's really about it. It's on him to figure out his own bullsh*t and deal with it.

If his issues are related to #1 or #2, then he should have taken that into account before he got seriously involved with someone so much younger than him. You aren't arm candy for him to show off at the senior living bridge tournament. You have your own social life that you expect him to be involved in, too, and he has to be willing to be involved. There's no excuse not to be.

If the issues are related to #3 or #4, then he needs to realize that issues he has with his parenting are his to sort through, not yours to suffer from. He didn't HAVE to estrange himself from his daughter. He doesn't HAVE to be available 24/7 for a 17 year old. If he feels guilty, he needs therapy, not make you pay for his parenting failures.

I'll say this from personal experience: my XH not wanting to be involved with me socially was a part of why I left him (amongst many, many other things). I got very fed up with being "taken but single" especially when I was young and in my prime. I wanted to go out and dance to saucy music, but it's hard to do that with a wedding ring and trying to be respectful of being in a relationship. I wanted to go out on double dates but it's hard to do that when your own husband wants to sit at home. People do look at you funny when you go out without your partner and assume you're either cheating or being cheated on. It sucks feeling alone while taken, and it takes a major toll on your self-esteem after awhile.

So, should you leave him? That's up to you. If you posed it as an option, my guess is that you're already one foot out the door. A nearly 30 year age gap is going to be super hard to overcome, especially if you're still in a time of your life when you want to be going out and doing things that he just physically may not be able to do. Plus, are you interested in having kids of your own? If so, where does he stand on that? And how do you feel about raising a child who will likely lose their father at a young age? If you're not interested in having kids then that isn't really an issue, but definitely something you need to take into account if you do.

You can't make him change his mind. All you can do is let him know how it makes you feel, offer some compromises, and see how he reacts. Then you either accept what he has to offer or leave.

ETA: Regarding SD, if my assumptions are correct about your ages, then I see why SD was likely upset after you two got engaged. If I had to take a guess, your DH pushed you as "stepmom" and not just his wife? A teen isn't going to react well to having someone that close to them in age acting as a parental or authority figure. Your DH majorly screwed up if he pushed that narrative and then "banned" SD from his house for not behaving in accordance to that.

It's a weird and embarrassing situation for a 16 year old. Yes, her father can do what he wants, but it comes with consequences. She doesn't have to have a relationship with you. She doesn't have to accept you as an authority figure. She should be respectful because you're a human being, but I can totally see where she could have been very weirded out by the situation. It's one thing when your parent dates someone younger. It's a whole other level of awkward when they move in and now have authority when they're born in the same decade as you.

It's real rich for him to come back now and try to play Father of the Year to his son when he didn't consider the ramifications of marrying someone 30 years younger than him. I know you may not see the issue with it, or maybe didn't at the time, but it looks super predatory and super creepy. For a teenage girl, it's not "ew my dad married someone younger." It's "ew, my dad is going after my peers who he could have watched be born and grow up through puberty before sleeping with them". It's icky at best and downright predatory at worst.

Your DH effed this up and it seems everyone else is paying for it except him. His daughter lost access to her dad. You don't have an equal partner. Your SS is stuck having to live through his dad's guilt. It's unfair.

I did go back and re-read the custody he has of his son.. it seems like it's pretty much 50/50 right?  three days every week and then every other weekend.

This is IMHO a bit different than a guy that maybe only has two weekends a month.. and wanting to be more protective of those few days a month that he gets.

and.. OP's post.. SS has a good relationship with HER and his dad.  hardly a kid on the wrong side of PAS.

Now.. if the son has a conflicting reason he wants his dad to be available.. that's one thing.  but unless OP sees these people for parties every weekend? and this truly is a special occasion.. why can't her DH be just a bit more open to compromise.

I will be interested to learn whether she gets any traction on the offer to bring the kid and a friend (but let them do something elsewhere.. I mean.. he is 17... they could take one car and he could drop them at the party and pick them up later).

If his dad is worried that he isn't showing enough gratefulness for his kid coming home after a vacation.. he could certainly plan something extra special the next day.

But.. it seems almost unnatural for a 17 to want his dad up his butt every day he is at his house.  I almost think as a kid that age.. he would welcome some freedom and time to just chill.

I had to go back and reread to make sure your SS is 17 and not 7.

There has to be something else going on here. WHY doesn't your DH want to be away from SS for that long? If it's just his own guilt, then you're the one suffering for that, not him. Or, is there an unspoken reason? Is SS a cutter? Use drugs or alcohol? Have unsavory friends?

I will say that I have a bit of a phobia about being away from home for the day -- what if something happens and I can't get back to feed the animals or let them out and can't notify anybody? I don't let that stop me from doing anything because I can inject logic into my thoughts (people know where I am and check in, the animals will be fine for a short period, and friends will arrange emergency care if need be). But still, I have to work around my own anxiety. Might it be something internal like that for DH?

Have there been other times that SS has spent 5 hours on his own? If so, why is this different? If not, then a conversation about encouraging independence is way overdue.

What is the point of having a partner if he won't accompany you to events that are important to you?  Why is hanging at home with a 17 year old (who you say is a mature, healthy teen) more important to your husband than attending a party with you, especially since you don't request it of him often and have had to attend other events alone?  I could maybe understand it if SS17 was long distance and was visiting for one of only a few rare weeks with your DH.  But he's with him every M-W and every other weekend!  That's half the time, isn't it? Why is he reluctant to leave an older teen who he sees all the time for more than a couple hours?  I'm puzzled that a mature, healthy 17 year old boy wants to hang out with his father that much.  Does SS never go out, either, or is it just your DH who won't leave SS?  And if he's worried that BM will badmouth him or PAS the kid, that's silliness.  If BM is going to badmouth him over leaving SS alone for a few hours, she's going to badmouth him even if he doesn't.  And if she wants to PAS the kid, she has him for more than enough time to do that.

Frankly, I think your husband is being ridiculous and very unfair to you.  I'd be inclined to pose those first couple questions I asked to your husband.  I would also let him know how hurt you are by his refusal to go to social events with you, and by his failure to prioritize his wife over what is definitely not a need of his son, and perhaps not even a want of his son.  

Are you planning on having children with this man?  (I ask only because of his comment that you're not a parent YET).  

5 hours away total,  from a 17 year old left at home, alone.

It takes one text message to 1 person. Next thing is 200 kids are at the house.

Perhaps that is what dh is thinking. If he is, he has a valid point. 

Here is what I would do, I would find a hotel local to the party. I would go, dh can stay at home with his son.

Every Birthday Party is a 1 time party. Just go, have a great time and tell dh to have a great weekend too.

But at 17  I didn't want to spent the weekend tied to my BF.  My friends / GF we're way more important then my parents on the weekend. I would be happy if my parents went out leaving me home alone (wouldn't be alone)  My SD's would love to be left alone ( wouldn't be alone ). 
There something off here in this relationship DH/SS.  
 

Your DH know the age difference when he married you. He had to understand your friends could be his kids.  He had to deal with your friends as you have to deal with his friends. Who could be your parents.   But that was your choice .  As a marriage couple he must attend this party as he attended party's with his ex, I bet he didn't tell the old wife that he would go and  only spend a hour at the party .   
 

The SS is 17. Come on . If his relationship with his son depends on his kissing SS ass 24/7. That no relationship.  That paying SS to come over. That not how you treat your child/ man   If SS will pull away never to speak to DH .  That DH fault   His bad parenting of SD  caused this problem. He gave her to much power and she used it against him. 
 

But also a 30 year difference between you and DD. As you are 30 he is 60. Where is this going ??  In five years he going to retire?  You are going to be 35? His income is going to drop.  You will be paying for SK . The older kids get the more expensive they become. 
 You don't want children of your own?   When he is 70 and you are 40. He not going to be doing much.   Hope he has lots of life insurance,  because if you stay you are going to need that to live on. 

Now.... inform your DH that his spawn is 17 and not 7yo.   His job, primary job, is to make you and the marriage  you share his priority.  Kids are the top marital responsibility though not the priority.  SS is cared for. End of responsibility.  

Beyond that, DH needs to be at your side for  this event as you are with him otherwise.

smh