I always thought I got on with my MIL. My DH and I have known each other over 20 years. We went out for a couple of years in our 20s then split up, got back together 6 years later then got married and have two DC. So my MIL is in her 80s now and I actually meet her on her 60th birthday (she had my DH in her 40s). Not that any of that matters..
Anyway my FIL passed away 3 years ago, until this point had always had a good relationship with MIL. We visited her and FIL loads during school holidays DH would do all their odd jobs etc while we there. DH had some mental health issues and we managed to get through those. MIL knew all about it.. Anyway just she moved in with her daughter and husband and their children (who are slightly younger than ours). DH and his DS haven't had the greatest relationship and I'm now worried that not so much my relationship but my DC with their DG is now strained simply because my MIL feels she has to 'take a side'. I've really tried to be friendly with my SIL but she just doesn't like me. And It think that because MIL lives with her - or next door - she's had to distance herself from me. MIL had a difficult relationship with her own mum and I think views her relationships with women as potential sources of conflict. it's a shame, but I guess I'm just quite sad. Nothing terrible has happened. I just don't want my MIL to have to take sides between me and SIL. SIL has said to MIL 'I'll never be close friends with (me) because we are so different'. But I've really tried - maybe too much. She got a Peloton bike and Iv'e got one - so I kept saying 'let's go on a ride together' let's all be friends. I have friends who are not like me. Anyway just interested to know others handle it.. to be honest if they weren't close family I wouldn't bother but I come from a large Catholic family -v very different personalities and while we don't live in each other pockets we are there for each other and we are polite to each other too. DH thinks its because they've got a bigger house and nicer cars so they think they are better than us. I don't think it's that simple though.