I think it's healthy IF you are dealing with mentally healthy people. BM over here is an angry, miserable nut job that neither I nor my husband want anything to do with.

Honestly, I think this question is very difficult to answer because every situation is different and it's just one of those things that you really have to be objective and look at the situation you are in. I think a lot of people on here, myself included, have been burned on what started out as good intentions. I would say tread lightly and stay guarded because she might genuinely have meant that she's glad her daughter has you... but that's today and could change in a snap. I think being civil is important if you can do it and I think the kids do well to see it, but I would steer clear of co-parenting with BM. Let your SO do that and just be friendly during interactions.

My ex and I are civil with each other and when DH sees him they are fine. If BS's dad lived in our same city or was more involved I would hope that we would all be able to get along for the sake of BS and our own lives. I would work hard to eliminate as much drama as possible.

Now BM is another story. She is a nut job. perio.dot. so there is no reasoning with her.

I am a step child on both sides and all of our parents got along. Initially my mom and the BM didnt get along but in time everyone got along. For me it was a really positive upbringing with not dealing with the drama.

Honestly when I found myself in the SM role, I was shocked by BM's behavior.

You always have to do what is best for you and your family and what makes you guys most comfortable. I think you can be civil and nice without being too involved with BM and her BF.

I may be way off base here, but the way I read your question is whether it is OK for your FIANCE' to interact with them.

If that is the case, I would say that if you didn't want him to be involved, you shouldn't have opened the can.

I am on the side that it really is important for ALL of the adults to be civil with one another, and help foster love and affections between the children and the parents but you don't have to be BFFs.

I get along great with BS15's dad. We have no problem communicating but DH has an irrational problem with my ex. They don't speak at all. SS7's BM goes back and forth between trying to be my BFF and hating my guts and stalking my facebook page for any dirt she can find. She doesn't find much because my rule is "I don't put anything on FB that I wouldn't want my mom to see and my mom is one of my friends on FB." I honestly tried in the beginning but it became such a chore dealing with BM because she is so freaking insecure that I now do it only under dire circumstances. And then there is the case of my divorced parents. They get along. Hell, they and their spouses have gone on group vacations with me and my boys. Nobody has a problem.

I thing it just depends. Err on the side of caution though. And try to maintain neutrality in front of the kids. Do the arguing behind closed doors.

IF BM is sane - sure it's a good idea.

Usually, if BM were sane our DH's would have stayed with her. So most of us have crazy BMs to deal with. They start out nice, then get crazy over time & we have to stop talking to them. At least that was my story. I had to stop talking to BM so I didn't give in to the urge to tell her what I really thought of her & smack her.