This man is forcing your kids to follow a set of rules that his kids are free to ignore.
He's allowing his son to disrespect you.
Your kids are forced to share a smaller room because his kid wants the room he isn't even using.

All of this is going on and you aren't married yet. You know what you're getting into before you say I do. Most people here didn't get hit with crap until after the wedding.

You're luck that your DF has his true colors before the wedding.

Change the locks on the house and move your kids into the bigger bedroom. If the "kid" isn't living there, and he can't respect boundaries, he doesn't need to have free access to the house. }:)

#1 - Change the locks on your house and don't give him a key. (he still may just wander in when you're home though, especially since you have children coming and going)
#2 - Set up the rules for YOUR house for this young man. Sit down in a room with your DF and "soon to be" SS (and all the kids) and explain all the rules. Have the rules written down. Review the rule list with DF 1st.

He doesn't have the right to violate your privacy (whether purse or bedroom, etc.). If he wants to use something, he must ask and ask politely.

#3 - We alway put a CAP on how much someone can spend at a dinner and include the beverage in that price (I have 3Skids, 1 BD). If they are not buying the meal - they had no sense of money and DH never would say a peep - until I stepped in one time and said something. Oldest SD would order 3 orange juices and claimed ignorance that she thought it had free refills. You DF should have said something right during that dinner to his son. I totally understand the head-in-the-sand. I get that all the time from DH and it stinks!

One time I tried this on my adult Skids, on Father's Day I said that the kids all should pay the lunch bill for his present. When the bill came I went to the restroom. I came back almost 10 minutes later and they were still trying to figure out how to pay the bill. It was at a Chili's too, not some expensive place. Oh, and I made them include my meal too -- for the Mother's Day they neglected - HA!

Get the rules of the house in order before you get married. and put it in writing and keep it!

OMG! 20 and HE decides who's going to support him from one moment to the next???? Good grief! If your fiance doesn't see anything wrong with this behavior, I doubt he ever will.
Going through your purse??? I went through this personally. Let me tell you, I snatched my purse from that little snot in front of God and everyone and flat out told her that if she ever touched my belongings again without my permission, I would either call the cops or break her fingers: her choice. Was it a popular reaction? Nope but, I was so floored by this kind of behavior that I reacted w/o thought at the time. Of course I was the bad guy. I didn't care. I was not raised that way nor would I ever put up with it.

You need to tell hubby your thoughts about this 'adult' kids behavior and find out exactly where you stand. Trust me, find out now before that ring in on your finger. Only you can change your situation. Been there and so done that!

Best of luck to you.

Walking in and out of your bedroom and going through your purse? NO WAY would he get away with that around here!! Put a stop to that right now!

Here is some information that might be helpful............

How to not to be the designated punching bag!
By Dr. John Townsend

Rule of the Universe =”You experience in life, what you tolerate in life.”

A person who puts up with bad treatment, gets treated badly.

Ask yourself – or a trusted friend or family member – if you put up with things in life that you shouldn’t put up with?

Do I allow others to treat me poorly, and not stand up for myself?

Do I not set any healthy limits with others; instead I laugh off their disrespect or say nothing, instead of letting that person know that what they said or did was unacceptable?

All of us should have certain requirements on how we want to be treated:

You want respect from others.
You will not allow others to talk to you in an inappropriate tone of voice.
You will not allow others to use certain disrespectful words towards you.
You will not allow others to put you in certain inappropriate situations.

Although it can be very difficult, it is important to stand up for yourself, and tell the others person(s) that you take responsibility for allowing them to treat you with disrespect, and that you will not be allowing this to happen any longer – and say it in a respectful but serious tone of voice.

Next, you need to enforce this! If we have trained others to think that they can get away with treating us disrespectfully, it will take time and effort to “retrain” them to not do this any longer.

They are not going to like the “new you” and they will let you know this through their words and actions. They will test and retest your resolve.

This can mean that you will leave the room, leave the party, leave the situation, not talk to that person for a while, etc... There needs to be some sort of immediate consequence for the other person’s bad treatment of you.

Be consistent and firm! Don’t back down no matter how much they try and get you to do this.

___________________________________________________________________________________

RESPECT: A willingness to show consideration, appreciation or deference to another person. To show deferential regard for.

In regards to respecting your elders, it's about choosing to acknowledge their years of being alive, their position in relation to you, and their life experience and insight as something valuable.

We all know that some people will never deserve our respect, but a young person disrespecting an older person shows a lack of maturity. A young person, who has good character, understands there are still ways to respect their elders despite the fact that the elder may not have “earned” respect.

If you don’t show respect for your elders, this in effect can mean you have been brought up lacking the qualities that have been recognised as needed in society’s interests, or you lack a caring outlook for anybody but yourself or only those whom you feel ‘deserve’ your respect.

If we don't respect others (especially our elders) we have no self respect. A younger person who does not respect their elders, is recognized as being selfish and shallow.

Concerning a parents/stepparents perspective on setting healthy boundaries with the kids.

True change can only come when there is “pain” or “discomfort” which challenges a person to change their behavior for the better.

The consequences of a persons actions has an important function in their life. Life works on “reality consequences”. True change comes only when a person encounters a negative (reality) consequence for their counterproductive behavior.

A person needs to understand they are in “control” of many of consequences for their behavior. They are in control of the quality of their life. If they understand they will experience negative consequences for unhealthy behavior, they have an opportunity - and the control - to make changes that will change this. When people “bail us out” or let us get away with behaviors that are unhealthy, rude or disrespectful, this is actually harmful to us.

In setting boundaries with your kids/stepkids, you are trying to help develop good character.

What is character?

Good character is a force that moves through a situation that creates good results.

A person with good character is emotionally stable and mature, has good moral and ethical qualities and strength, and is intellectually competent. Their influence in a situation is positive and productive.

People with mature character have traits of integrity, responsibility and courage. Character is the sum of a persons abilities to deal with life. Reality makes certain demands on us. How successful a person is in meeting the demands of life, shows their level of character development.

Unhealthy marriage relationships exhibit the following:

1. Constant detachment or disengagement. Problems in getting engaged emotionally
with one another from the heart and willingness to work through issues. One person has a behavior pattern of pulling away a lot - or both partners avoid one another when things get difficult.

2. Deception and dishonesty. One partner has a pattern of frequently lying, betrayal or dishonesty towards the other partner. This is a serious breech of trust in a marriage, and is not to be taken lightly. It is a deal breaker if it isn’t resolved.

3. Lopsided roles of power or responsibility. One partner takes on a “parenting” role towards the other. This can happen either because the “parenting” partner has a co-dependent personality and feels the need to be in the “control” position with the other person, or it can happen because one partner acts childish and doesn’t seem to be able to function in a mature manner. Because of this the other person feels pushed into a “parenting” role by necessity. Either case is unhealthy for the marriage.

*These also apply to relationships between family members and others – not just in marriage relationships.

Get this issue under control before you marry him or it's only going to get worse. A little back story. A few years ago when DH and I got engaged, SD (25 at the time) lived at home. We decided we'd lease a small home for her so she'd have her own privacy and we would have the same as newlyweds. I didn't want to move in with her and DH. SD had a fit and wanted to stay with us until she finished her studies. So we got married, I moved in and she proceeded to do every evil, nasty and petty thing she could do to push me out. The moral of this story . . she was a trouble maker before we got married, and things only got worse after the fact.

Your fiance's son is pulling his little stunts to disrespect and diminish you, and to show you he is control. Your fiance doesn't have a back bone to stand up to him, so you'll have to. Enforce new house rule and make sure he doesn't have a key. And if he ever goes through your things again, set him straight and ban him from visiting again until he apologizes and learns respect. I agree with Not the Mom . . above. A person who puts up with bad treatment, gets treated badly. Make him honor and respect you. Period!

I feel marriage is challenging and difficult enough as it is. Mean spirited problem steps that add drama and negativity have to be dealt with accordingly so they'll know you're not going to tolerate their foolishness or disrespect. Life is much too short for BS.

I am in the same boat as you. My 20 year old step-daughter recently moved back to our home. Before she moved in she said things would be different; nothing has changed with her. Granted she is only 20 years old, but what frustrates me the most is that my husband just lets it happen. When he does try and talk to her about her actions, he talks to her in a "baby" voice and it drives me crazy because he is starting to treat me more like the child than she is. Since she has moved in this last time, I told my husband I'm not going to put up with it again. Last time this happened we ended up going to counseling and he admitted that when him and I had an argument he would get his daughter to be against me too. It took along time for me to forgive this behavior and now I see it slowly creeping back into our lives. Before his daughter moved in, our lives were great. Now I'm seeing the wedge again and I won't be treated like that again, even more now than ever that I know I'm not going "crazy" over how I'm feeling such negative vibes.

OMG! after one 4 1/2 year period, with two of DH's adult "children" living with us and our marriage almost in the toilet, i would NEVER, EVER let a skid move in with me again. i would never let my own adult son move in. there are other ways.