the tricycle
A way of referring to sexual intercourse with two (2) female partners, commonly called a threesome. Famously referenced in the CBS comedy "How I Met Your Mother". The first man in a group of male friends to pull off this feat wins the belt as a reward for his skill with women. 
Steve: Dude, where were you last night?
Dan: These two girls were hot for me. We all went back to my place and I rode the tricycle with them. I guess I win the belt!

Steve: Dude, I saw those two chicks checking you out. Which one likes you more?
Dan: They're both into me. It's a tricycle!