My BIL walked out my SIL and very young children for OW. He gaslighted my SIL and made her think it was her fault. SIL blamed herself, in-laws blamed her, children wet the bed with stress, SIL was in a really bad way. SIL later finds out he has been having an affair since youngest was only a few months old and would have left her earlier had her parent not died. He had multiple opportunities (in marriage therapy when SIL asked him directly) to admit it but he did not and still has not. Fast forward a few years and he is now with OW. After several short term rebound relationships, SIL is thankfully now in a stable relationship and has tried to move on but is damaged. Kids are on the face of it ok. I’m still very close with SIL and have not abandoned her. DH’s family find it challenging that we remain close. I’m not really interested in getting to know the OW despite her efforts to ingratiate herself with me. No one in the family talks about it and if they do, it is still SIL’s fault for working too
much, not being attentive enough etc Infuriating! No one dares asks how they met which is a normal conversation starter. BIL is very charming and gregarious and uses this to gloss over the fact that he’s been a lying cowardly sh*t. SIL has kept quiet to protect her children and has not bad mouthed her ex but has confided in me. TBH I’m not sure I would have been as dignified as her. MIL thinks the sun shines out of his backside. BIL has basically been allowed to get away with it. DH is close to his brother and I’ve said his relationship should of course continue but I’m not making any effort beyond normal family gatherings. AIBU??! Everyone has seemingly moved on but I can’t get over the injustice of it all. If this had been a friendship group, I would have cut all ties with him but at the end of the day he is my DH’s brother and I don’t want to cause more damage to the family. Any words of wisdom?