Sorry, I haven't read the full thread yet but I read all your posts on this and the other thread. It gave me anxiety for you! I agree with those who said you need to approach this directly with your daughter rather than trying to pretend it is ok, otherwise this will keep happening and eventually her bf will wear you down and make you very unhappy, and possibly steal from you. I think there are four pieces of information you need to communicate to your daughter:
- Her boyfriend was disrespectful to your husband in his own home, calling him unmanly, and other examples of trying to dominate your dad in his own home. That is not ok and your husband is unwilling to be treated this way in his own home.
- Her boyfriend went into your private bedroom without permission as you know because he mentioned a book on your bedside table that you did not take outside the room at all. You feel your privacy was invaded and your hospitality was not respected. That is not ok, and you will be putting in new boundaries to protect yourself from such behaviors.
- You observed her boyfriend steal something from a shop (or whatever your evidence is; I'm going by how I interpreted what you wrote in your other thread).
- Unlike other guests, her boyfriend and his parents overstayed their welcome and did not contribute to food.
You said that since your family has a habit of welcoming guests into your home, that it is difficult to justify NOT letting your dd's bf or his family stay. However, it also sounds like your other guests don't treat you like this.
Your dd is probably going to be defensive about her boyfriend, from what you describe of her. But you really cannot allow yourself to be taken advantage of, like this. You want to treat her just the same as you always treated her, like a beloved daughter who has the run of the house. But she is putting her boyfriend's feelings over your wellbeing and her boyfriend has some risky behaviors (from your perspective) so you can't do that any more. You have to stand up for yourselves.
I think you can take one of two paths here. The first is to communicate, directly or indirectly to your daughter, that her boyfriend and his family will be treated differently than other guests, because they behave differently than other guests. They overstepped their boundaries and were not respectful towards you. Your daughter can explain it away: he didn't really steal, how do you know he went into your bedroom, etc. But all of that is not important. What is important is that it is YOUR home and YOU are uncomfortable. So that is what you keep repeating. This is our home and we feel uncomfortable. We don't want bf or his parents here unless we are here. In future, they are only invited if we say they are invited. We can't force them to chip in for food but the food they eat is what we offer, they can't just go into the refrigerator or pantry and pick what they like. And for the same reasons (all the above), they don't come unless we invite them and they only stay as long as we invite them.
The second possible path is to start shifting your approach to guests altogether. You are getting older and unfortunately that makes you somewhat more vulnerable. You will, at some point, be living on your savings and likely have less budget to treat several random people to food for days at a time. Maybe you have just outgrown the practice of all your son's or daughter's friends to stay for long periods and having them reciprocate by buying a fish and chips occasionally. At some point, your children will start having children. Do you want all your son's adult friends staying in the house if your grandkids are there? I think you will find you do not. So maybe now is the time you start that shift.
I see that an underlying issue is your worry that your dd's bf is a bit controlling and that if you set boundaries she may cut you off and end up in a situation where she is unable to leave him if she wants to. That is a valid worry but I don't think allowing them to overstep your boundaries is helpful. It just communicates that what he's doing is ok. I think you can, in general terms, tell your daughter that you are always here if she needs you, hint hint. And, separately, that you are allowed to have boundaries where young men she is dating do not get to be rude to your husband, show up and stay as long as they want in your home, bring guests you didn't invite, or go into your private spaces and rummage among your things.
One way to think about it, is that you setting boundaries with the bf and his family is a way of modeling to your dd that it is normal and healthy to have boundaries and that maybe if he doesn't allow her to set boundaries (expects her to always cook, dominates her) then that is not a normal behavior on HIS part, not YOUR part.
Sorry my post is so long, hope it helps.