Have a heart to heart talk with DW.  Tell her you need some tim3 with her each night.  For her to try arrange some time with you.  What she wantes you to do to help her out, to help get this time.  You need a date night every other week, movie, dinner, or other fun thing to do.  Try to  work out something for both of you to get a win win 

Your wife is failing as a parent and a partner.  She needs to tell her children that while they don't need to like you, they do need to respect you and not ignore you, and she needs to impose consequences if they don't.  She also needs to make some room in her life for you.  Spending time with her husband should take precedence over phone calls every single day to family or church group.  But I'm not sure why you're sitting in your man cave for hours after work.  Your wife has been with her kids for many years - I can't imagine that she needs a few hours every night to "bond" with them.  If anything, they need time when you're around to bond with you.  Maybe you're never going to have much of a bond with the teenager, but I've got to think you can work on a relationship with a 6 year old.  

This sounds super lonely. I agree, talk with your wife and work with her to place ground rules in your home. Living on eggshells in not a viable long term solution. Believe me. I know. I think couple's counseling would also help clarify things and offer best practices. The trick is that both parties have to be willing to be honest with themselves. 

You feel like a stranger because you're behaving like one. How do you think your wife feels when you hide in your cave rather than spend time with her and her kids every night? 

Start by talking to your wife about getting the kids to respect you. Ignoring you isn't respecting you. They have to respond. Be clear about your expectations from her and her children because she's not a mind reader. Start spending time with them in the evenings - ask about their day, help cook dinner, lend a hand with homework. ANYTHING just show them you exist and you're not going away! At the moment, you are making yourself so invisible that (I hate to say this) is it any wonder they don't "see" you? You are the adult here so affirm your place in your own home. Things won't improve overnight, they may not improve at all but if you do nothing and keep on hiding out you can be sure that nothing will change.

Good luck.

It's odd that what should be a really special time for all of you sounds so ho-hum...so ho-hum that you're thinking of leaving. Is the love gone? Or have you just gotten into bad habits that make marriage a drag?

I say tell your wife you miss spending Saturdays with her and her kids would love to have back some of her time so you can all prepare and bond with the baby as a couple and a family. She might be touched -- many men want less time with their wives! She may change her priorities if she's flattered.

I guess what I'm saying is...make her want to be with you and her kids more than she wants to be on the phone. What is it about her church work that makes her put it above family? Figure it out and then cleverly show her how all of you can provide the same boost as baking cookies for a church mud sale.

With a baby on the way, the whole dynamic will change. That baby can bring you together or drive you apart. Do you plan to be a hands-on dad? She's gonna need help with four kids, a job, church stuff, etc. Why not use this happy occasion to reset what sounds like a marriage in a rut? Start making the marriage what you want it to be now before the baby gets here.

Who is tending her kids while she's on church duty all weekend? Someone is enabling her to be unavailable. If it's you, you need to cleverly shift responsibility back to her. What if you said, "Hey, the kids and I would like you to go with us to the park at 2, so can you be available? We'd love to have you." You're not asking her to cut off her church time. You're asking her to be available for her family. When 2 p.m. comes, make the "wrap it up we're heading out" hand motions and see if it works. If not, you might have to be more assertive and ask for what you need. But be diplomatic first.

I never understand people doing so much for a church when their family waits at home. It's fair to ask her to reduce her commitment so you can ALL bond with the baby. Don't demand, don't scold. Try to make her see that her FOUR KIDS (geez that's a lot of kids) are their own congregation and soon they will be grown and gone and she will have spent those years on church stuff. Tell her she can always go back to church work when the kids are older, but you don't want her to miss these exciting years with your new baby and her kids. (Never make it about you...always make it about her kids!)

It sounds as if you have a typical teen and there's no helping that! But you also have two other skids you love. This baby can be a reset for all of you (maybe not the teen). Engage the younger kids in helping with their new sibling. Try to stoke them for having a baby in the house. Stoke your wife too. No one with four kids should spend disposable time elsewhere. It's selfish. Why did she have those kids, and then another, if she didn't want to live up the the responsibility of raising them? Try to pull the "charity begins at home" card without making it sound like a judgment.  

Oh, and tell her new rule: no phones at the dinner table. This is where you have every right to make a rule without negotiating.

It is ridiculous for a grown woman to act that way toward her kids and husband. What an example she's setting!

She needs her phone time limited just like a child. She is being rude, especially on nights when YOU cook.

So your wife has made everyone and everything else a priority over you, and instead of standing up and asking for your rightful place at her side, you hvae stepped back in an effort to be "nice".

Been there, done that, and have the divorce papers to prove it.

Marriage isn't about being "nice". That's what dating is for. Dating is for having fun, losing yourself in each other, being silly and drunk with puppy love.

Marriage is work. Marriage is figuring out how to make a business work while also realizing that you have to sleep with that person at the end of the day. No good manager of a business can just sit back and let everyone else run the show. They HAVE to communicate their wants and needs, and they HAVE to make tough decisions.

There is NOTHING WRONG with asking your wife to put away the phone when she gets in bed with you. There is NOTHING WRONG with sending the kids to their bedrooms at 8pm to entertain themselves. There is NOTHING WRONG with telling the kids they can't come in your room, even if they knock first.

There IS SOMETHING WRONG with slinking into your man cave every night in an effort to make your wife happy. You compound the problem of being at the bottom of the list by putting yourself at the bottom of the list. When you aren't present, other people will fill the spot you leave.

So start with being present. Start easy by just being in the same room as your wife and SKs. Sure, it may be awkward at first, but you're going to have to get used to being around them. Once that baby comes, you won't be able to take the baby and slink away. You'll have to BE THERE with them. So, push through the awkwardness.

By being present, you'll pick up on inside jokes. You'll see how they all interact. You'll have opportunities to provide input. And, you'll also give your SKs the opportunity to be little demons to you in front of their mother, which hopefully she'll see and put a stop to.

You will also show the kids that you aren't going anywhere. That they don't rule the roost with Mom. That they aren't the most important people in her life. Don't get me wrong; they are her #1 responsibility. You, however, are her #1 priority, and vice versa. Your wants and needs trump their wants. Their needs trump yours. No child needs three hours exclusively with Mom every night, but a marriage does need consistent work and interaction. Trim down the kids' WANT of Mom because your marriage NEEDS her, and you.

So start with being present. After you have mastered that, then we can talk next steps.

It takes time to become part of a family unit that already existed before you came along. Also, your wife needs to put in the effort to create a new family unit that you are part of. I've read that it can take up to 5 years for a "blended" family (I'm not a big fan of the term) to come together. You should talk to your wife about how you feel, emphasize that you'd like to be part of the family unit, but you need her help in making that happen, and also remind her that you all need to prepare to become a new family once the new baby arrives. 

I would also try to do things with the children individually, to get to know them. Start with the younger ones, since they might be more amenable. Make it clear that you are not trying to replace their dad. 

One question - did you move into the home they shared before you were around? I think that can make things even more challenging, because they all have history in that location before you arrived, so for them nothing has changed. 

Finally, mom shouldn't need that much time alone to bond with her kids...her focus should be on creating a family. You give her a lot of alone time to do her own thing, but you need to work with her to create time to do things as a family.