A man who ejaculates nearly immediately upon initiation of sexual intercoure; eg., after one or two thrusts.
'Damn girl, that man ain't never gonna last long enough to please you; he's a one pumpchump!'
By Mellisa
One Pump Chump
a friend who has his first ever relationship in his life, and his first time fucking he only lasts thirtyseconds in her vagina
josh: so i heard you lasted 30 seconds sean: meah... she was tight josh:yea okay you dont thrust once and call it quits you one pump chump you go back and pounce on it