When a guy and a girl are going out and the girl just hangs all over the guy. The guy doesn't care. The girl is useless and hangs there much like a keychain to a backpack.
by TangoMaureen December 10, 2005
The visible print made by a man's penis on the front of the pants. The phallic formation seen through a man's trousers, shorts, or jeans. See also DICK PRINT
by q.wsmith March 31, 2010
In the act of threesome with two males and one female. A keychain happens when one male drives his penis in the females vagina, as the other male drives his penis in the females anus all at the same time. In which creates an effect of a keychain.
by AccurateDefinitions4578 January 12, 2015