Need advice:

My daughter has a preschool classmates birthday party this afternoon. In our marriage (and until now in our separation) I typically take her to these types of things, for a variety of reasons. This time
I’m having my H take her while I have fun with friends.
The thing is that I haven’t shared our situation with any of the parents at school. I’m only superficially friends with them at this point and it’s a pretty gossipy scene which I don’t care to be fodder for. My H is fairly unfiltered and I’m concerned he might mention it while chatting with them. My gut is that it’s a risk I’ll have to take because to ask him not to mention it seems...the opposite of detached? I don’t want him to say anything, but I’m afraid if I ask him not to then it’ll give him the impression that I’m still in it and not accepting that we aren’t together, or something like that. Thoughts??