My family does and our closest friends are actually the couple I/we first started swinging with some 25 yrs ago. So, no secrets there, LOL.
My mom and I had our battle about it, but she was able to accept the situation to see her grand-kid-s. She never approved.
My dad just said, "Not thrilled." Yeah, that kinda hurt.
My MIL just continued with "That slut that married my s-o-n" as she has had that opinion since we first met. The first time I met my MIL, I was topless in a thong bikini at the beach by The Caves. She walked up with my then bf , now husband. I did not know she was with him and with me facing away, I spout off, "Hey honey. How do you like my ass in my new bikini"