At the time I was single and unattached, it wasn't exactly a decision that I wanted to swing.
In my early twenties, after I broke up with my fiance Red and moved out, I started dating another guy David (who is now my husband). After the second date I was incredibly horny, but he was too much of a gentleman to put any moves on me, so I went back and fucked Red. It was good, easy and so uncomplicated because we had been fucking for years before. The next date with David we ended up in bed and I stayed the night. After I left his place the next day, I got with Red again.
I kept Red up-to-date with what was going on and he was ok with it because he still loved me and wanted to keep getting in my pussy:). David figured out what I was up to (turns out he reads me perfectly), and to my amazement he said he was fine with it. So I started it, but David made it possible.
Fucking two guys who cared for me at the same time with both of them knowing made me self-confident and left me wanting as much sex as two guys put together. It led to me overcoming my jealousies and after two years letting the guys play with other women, me discoving my Lesbian side and playing with David's lovers, and having sex with three other different guys. Ten years later, Red, David, Lora, Clair and I are in a poly family.