Not BM (because we’ve been in the same room exactly once), but SD. The “remember when” game was definitely used as a way to exclude me. But DH played right along because it meant SD was paying attention to him. Took a major meltdown before DH had to acknowledge how awful it was for me.

Can’t do anything about BM’s (or SD’s) game playing, but your DH seems to deflect the nonsense instead of getting caught in the trap.

BM here used to do that (I haven't seen her in several years) almost obsessively. An example was when we were all at dinner together a long time ago she kept looking at DH and saying things (repeatedly) like, "Remember when we went to Switzerland and . . . .?"  Then she'd look at me and tell the story. Then she asked, "Have you ever been to Switzerland?" lol. As our old friend here used to say, wash, rinse, repeat.  It IS bonkers. 

When we attended SD's wedding, I sat next to BM at the rehearsal dinner. On purpose. Because, from the way everyone was acting toward us, I knew they had all been told that DH and I were monsters. So, I  chatted her up, then I unloaded on her about our trip to Europe. muhahhaha. We were treated horribly during the whole event, but I very publicly hugged her when we left the reception. Petty but enjoyable.