I am a single male. I met a girl at work who was in a commited relationship(engaged). We were drawn to eachother physically. Intelleactually we were more than compatible. Nerds too . We hung out some and let me know they were swingers. We did some stuff and spent some time togather and when I felt comfortable( I am very private) I told her I was bi and it turns out her fiancee is as well. hmm freinds and friends and friends. My best story about that.
Edit: Sorry... just realized this question is reffering to couples only. Remove if you need to, I would but I do not know how atm.