I posted here yesterday asking for opinions regarding swinging until some gentleman pointed me to correct subreddit.
As I mentioned in that post, the wife and I are open minded to some point, we agreed to have a "free day" where we have sex with whoever we want as long as we don't have to know who were they.
My choice was her sister and her best friend, I didn't see any problems with that until I heard some valid opinions about how I'm playing with fire, I guess they were right.