When you yourself are stuck between two people that want you (be it sexually, emotionally, for a relationship, or simply due to territorial instinct), and consequently hate each other.
Works for either two women jealous of the other for being around one guy, or vice versa.
Dude: "Oh, man... is that Karen??"
Bro: "Woops... yea... she totally just saw me with Steph!"
Steph: "Who's Karen???"
Dude: "Wow... well, I hope you enjoy your peanut butter and jealousy sandwich."
This is a sexual action you perform on someone who is highly allergic to peanuts. About an hour before you have sex, take standard peanut butter and spread it over your entire penis. Next wash off the peanut butter so that it is not visible, but the residue still remains. Then you have sex with the special individual, who will not notice right away, but the next morning she will feel very uncomfortable. When she checks herself out she will see a large rash in her vaginal area from the peanuts and think that you gave her herpies.
Dude: "Oh, man... is that Karen??"
Bro: "Woops... yea... she totally just saw me with Steph!"
Steph: "Who's Karen???"
Dude: "Wow... well, I hope you enjoy your peanut butter and jealousy sandwich."