Does all this ring alarm bells for you about boundaries?
Have been married to DH for 12 years, together for 20. PIL started out fairly friendly but distant, and have got progressively less welcoming, more excluding, and more aggressively unpleasant towards me. FIL is very arrogant, entitled and misogynistic in an old school tie/ bulldoggish kind of way. MIL is terribly grateful for the attention he bestows upon her, and is inclined to use him to enforce things where someone might (resonably) say no. FIL very aggressively enforces what MIL would like, talks over any objections and isn't above a bit of aggressive shouting to make sure he's won.
MIL tries to be way, way too close to my DH and individual grandkids. MIL has always had weird boundaries, being overly close with DH and frustrated/angry that her daughter (SIL) has kept her distance since her teens. She kisses DH and grandkids all on the lips (including my 50 year old DH, ugh), treats them like dolls dressing them up, feeds them by hand, is suffocatingly physically close. Always wants them on her lap, always has an arm around one or more of them. Always wants time with them alone, away from the gaze of other adults. Was incensed when DH started organising his own doctor and dentist visits as a 30 year old. Wanted to go in and change his pyjamas and give him a bed bath when he was 44 and had covid when we were staying at their house, and got really angry with me when I repeatedly suggested he could do that himself and she should really probably try not to catch covid. She then crowed about having done it anyway expressly against my wishes when I went out, saying that DH is her son and she'll do what she likes.
FIL aggressively enforces her "right" to such closeness, and has been aggressive towards me since DS9 was a baby because I've repeatedly stonewalled/ grey-rocked any suggestions that MIL should have time alone with DS, and have never held him in place so MIL could kiss him on the lips (in fact I've always made sure he's nowhere near her when this seems likely).
One of SIL's children (aged 13) is persona non grata because he's challenged MIL's boundaries and the rudeness of FIL's enforcing. MIL no longer kisses this child on the lips, nor seeks physical closeness with him, interestingly. He stays out of her way at family gatherings. The other GC (including the 17 year old) are still very much enmeshed with her, all over her like puppies, and she lights up when they're around.
DH has multi-year parts of his childhood that he has blanked out, where he can remember literally nothing. He is too frightened of his father's response to tell his mother not to kiss him on the lips. Over the years she's said things like "It's to show he's all mine" to me, after she's ostentatiously smooched him. DH finds it intrusive but is too afraid of his father to ever tell her to stop.
MIL and FIL are very aggressive towards me because I don't allow DS9 to have unsupervised time with them: they've recently banned me from their house. DS9 goes to visit them with DH for a couple of hours at a time, when we visit their city once or twice a year. I have told DH that it will be divorce proceedings the instant that he ever allows DS9 to go off with MIL unsupervised. DH agrees that the attitudes are strange, and so far has successfully enforced zero time for DS9 alone with MIL or FIL.
This all comes across as very unhealthy, right?
Generally I try not to dwell on it all too much, but I know that at some point they will be demanding that DS9 visit them alone, and I really don't want that to happen. I also know that DH is likely to be unable to stand up to his father if FIL decides to force the issue.