Jealousy is my drug. For two years I had a husband and a boyfriend who were both monogamous with me. (I worked hard to keep them satisfied emotionally and physically.) I was jealous anytime a woman looked at my husband or even complimented him to me. (He is in shape and good looking.) One day when with a friend, she said to me that it must be great to be in bed with him. It still is burned into my mind how jealous I was, and out of my mouth came, "It can be arranged." At that point I realized 1) there was not going back, I am a woman of my word (plus I knew hubby would a) find her attractive and b) have sex with her if I told him to), and 2) how much I wanted it, to feel what it was I was afraid of. (Me choosing the woman for him to do this with did give me a sense of control.)
Long story short, they fucked numerous times over several months and I looked forward to it each time with a knot of excitement in my stomach. Longer story short, we made it a game of dating women together with the ultimate goal of hubby having sex with her and me watching (I wanted to see it!)/participating. Women were willing to screw hubby, and they did, but most didn't want me there. Those that did opened me up to my Lesbian side, and one woman, Clair, joined us to make the now four of us a family rather than just a wife with a guy on the side.
Even now, I get jealous and it makes me excited.