1 definition by Balloon Knot29
Placing your thumb over the penis just before ejaculating and holding it for a couple of seconds. When you release your thumb you can shoot your wad further.
You are having sex, you are about to cum, pull out place thumb over tip of penis. Wait a couple of seconds and release towards target. This is a thumber. Lets you shoot further
by Balloon Knot29 December 11, 2008