my OH has a child with his ex. we have been together 7 years. She has been married getting divorced and has a new bf, who isn't really that involved and none of us have met him yet. recently she has started trying to reminisce with my SO about when they were together. She did this when she was with her husband but only when he wasn't around and I was. now she is starting to do it again. she has done it the past few times we have gone to my step daughter's activities and again last night we all got together to take the kids trick or treating and half the time she was just talking to my SO saying doesn't this bring back memories or remember when we did this and that. he really didnt know what she was talking about and her soon to be ex husband just rolled his eyes like here we go with this crap. it made everyone a bit uncomfortable and no one wanted to say anything because the kids were with us. but I really don't get why she does it when I'm around. when I'm not there they hardly talk and she treats him like crap. I'm not really sure if I should say anything to my SO about it and have him talk to her about it to try to get it to stop.