paper cup
A girl/guy who you hook up with a couple times and then move on. You get the term "paper cup" because you use paper cups once or twice then throw them away.
Example:
Girl- "Yeah, we hooked up at the party but I haven't heard from him since."
Friend- "You're his paper cup."
Girl- "Yeah, we hooked up at the party but I haven't heard from him since."
Friend- "You're his paper cup."