Thank goodness this place exists!

So...my DH and I have been married 5 years. His kids are 24 yo (MTF trans) and 20yo dau. The oldest sort of lives in their own world, but my SD is another story. I have tried to get her to like me, but she only seems to act like she does when it suits her interests. Long story, but Thanksgiving weekend  2019 DH got a message from BM that their daughter ran off with her new boyfriend....after a physical altercation with her mom that left BM with bruises and a black eye. DH and I were shocked,  never imagined SD would/could do this. DH made calls and got info to find her so we then went to find her (they live out of state). After we found her, we took her to her BM's house...my first time meeting her. Since that time DH and BM have developed what I thought was a good co-parenting relationship, considering that even though SD was 18 at the time, she was still in high school and lived at home. BM seemed like someone I could be friends with and I didn't feel threatened.  My ex and I have a good relationship and work well co-parenting so I know for some people it is possible.  Anyway,  fast forward a bit and SD leaves again and basically moved in with the boyfriend at his grandmother's house. She doesn't call her dad often at that point,  doesn't answer when he calls...DH and BM are communicating and to me seems normal in that situation of checking on SD. Well...one night DH and BM are on the phone and I hear DH telling BM he's sorry to hear that....and when they hang up I asked about it.  BM told my husband that her boyfriend cheated on her....I let that marinate a while.  I can't find that to be appropriate.  I just can't. But I didn't say anything about it yet.

Fast forward to this past October...SD marries the boyfriend and their baby is born in November. We went for the wedding and I volunteered to make her bouquet and other flowers for the wedding. We were of course in the presence of BM. Nothing odd happened,  but I was not very comfortable around her because she thought it was ok to tell my husband about her BF cheating on her. But I made it through the day. Well...the baby was born in November,  a bit early but healthy.  We go visit and have to spend some time at BM's house in order to see the baby. Then we go visit  again at Christmas time and we spend much more time at BM's than I am comfortable with....even playing games, Family Feud of all things! At one point I'm  holding the baby and they all decide to go into the kitchen to play another game that they need more floor space for...meanwhile,  I'm  still there, in another room, holding the baby....which made me VERY uncomfortable. 

After that, on our next visit my husband could sense I was not a happy  camper.  I told him why...back to BM telling him she BF was cheating on her. He brushed it off. Said she probably just needed a friend and that it was nothing....that he just wanted a relationship with her like I have with my older kids dad. But the difference is we only get together for events...like school concerts...and we don't sit together.  We have never played games.  The one time we had a meal together is when we were having issues with a child and w we re at their house discussing things. My ex and I do not discuss our relationships...its not appropriate. 

Well, we went a few months ago and it happened to be SDs birthday.  We took her out to dinner several times and the day we were leaving was her actual bay. DH wished out loud that we could have a cookout to celebrate.  I was being sarcastic and said maybe we can have one at BMs house.  He thought it was a great idea! Called her up and added her. She thought it was fantastic! The next morning he left our hotel and went grocery shopping to get everything. I was fuming.  But I smiled through it. He knew I was uncomfortable, though.  

And we recently went again,  this time for SD high school  graduation.  And we sat with BM. And we were all together at SD's apartment afterwards.  But while at the graduation,  I was sitting between  DH and BM....until I made a DH trade with me because I was tired of leaning back while they were talking.  DH would speak, first looking at BM, then at me and honestly I felt like I was in the way.  Later DH said he thinks I get jealous when BM is around....  I bit my tongue.  I already told him once I was uncomfortable.  I don't know why he can't  get it.....

I'm sorry for venting sooo long, but I really  don't have anyone I can talk to about these things. 

Any thoughts or advice?

Also,  I am sure SD LOVES it....seeing me uncomfortable and her parents googly eyed talking to each other about the grandchild.  Also, BM has a new BF and SD seems to enjoy talking to her dad about it, telling him how often her mom is out on dates, like she's trying to make her dad jealous of the new guy....

Oh, and BM said we need to do another cookout next time we're there....I don't know if I can handle more of this!