[socolais]

You didn't mention the other husband's reactions to the events of the evening. I can imagine that they're "out on the town" and in serious party mood and they've been fantasizing and role playing about sexual group play. She sounds assertive and saw an opportunity to live a fantasy. I suspect he got taken for a ride by her enthusiasm, and didn't want to broadcast his mounting discomfort out loud. When they got back together, his body language let her know it was a good time to call it quits. They've probably had a lot of discussion between them and still have much more to go.

I think it might help for you to disclose your lifestyle experience to her and all four of yall get back together and have a serious group discussion.