So back in October I posted about basically internet vibes giving off that HCBM and her troll husband were no longer together.
I was right.

Over the weekend the woman I had seen him with online in various posts over the last nearly year, made them her profile picture with comments from several folks referencing them as "cute couple" etc.
We don't know if the kids know. One is at home but 20+ years old the other is nearing adulthood at home still. She will be down for Easter.

Would you bring it up to the kid or continue playing dumb even though it appears to be somewhat out in the open?
I didn't come from a divorced family and so I'm unsure how big a deal it is if your stepparent and your parental parent separate. The troll husband has been there a significant amount of time, but she is not a sentimental person or in my opinion very bonded to anyone. I can't imagine this helps the bonding aspect of her personality, but then again, my perspective on teens is they don't really care about things outside of their little friend world, if it doesn't really affect them much.

My gut tells me, DH needs to STFU but if there is any heartache or what have you, I'm sure he'd like to be there for his kid and let her know it's safe to talk to him about her feelings. 

Tell me your thoughts please.