I remember one day, two friends wanted to come over and do a beer evening (or whatever)... They asked if they could come over, they were immediately like "you wouldn't let friends come over hand have an evening at your place, you are not that kind of friend". That was so weird, because it was never an issue when one of them came and occasion just didn't occur that we would gather at my place (especially because they would get bored easily). At first I thought "wow, that's rare, how cool" and then I realize, something was weird, because he immediately assumed some bad about me. I have a conservative family and my parents don't like to see alcohol in our house and I would get into super troubles if my parents found out. I asked them before if they would come over with alcohol, because I would get in trouble and the guy immediately complained "I knew you would be a stiffler like that and judge us" etc... He then said "no, no alcohol". And what happened they came over with alcohol and sat in my room at the same time I was sweating and felt like ice was running down my spine everytime my parents passed my room. Finally I said "hey, ok, it's enough dudes, I hoped you enjoyed your drink, but we need to leave and go somewhere, you don't know what happens when my family sees us".
Of course they immediately guilted me and blamed me to be a bad friend. I then asked if they didn't do it at their place and their answer was "are you stupid, I can't do that at my place" (immediately like I had accumulated another issue in their eyes). The other guy answered the same. So I was the idiot with the super conservative parents who was guilted and portrayed as a bad friend for the exact same issues they had at their house. Just that they found someone with weak boundaries they could use for their convenience. I felt like an idiot. But for being shamed and held for an idiot at the same time.
On another occasion one of the two guys asked the other if he took pick him up from a place because his car broke down. The other guy didn't even bother to call me, because I wasn't in the same ingroup or whatever. What they did though is blame me for being a guy who would never do that and they are so much better friends. I didn't even own or car. Nor was I well off enough to buy one in the foreseeable future. They just glorified themselves for having a car and being better people at the same time.
Years later they would bring it up "I never felt you were the type of guy who would do that for a friend".
If you think that you friends will realize how absurd their breaches of your boundary is, you might be as foolish to ask a piranha to please consider to stop nibbling on your flesh.
A father of my friend kind of summarized it very well ( I might butch the quote, not a native speaker), he said "people call you an asshole for not doing as they please, that's enough for them most of the time to put you in that box"