look up any word, like half chub:
 
1.
cum burn occurs when sperm is left on the skin long enough to dry, causing the person to rub long and hard enough to irratate the skin turning it a red sun burnt color
(1) I seen a chick who had massive cum burn on her face today.

(2) Put your shirt on dude, you got cum burn on your back.
by Random C October 19, 2009
 
2.
When a man cums so much in a day that his cock has a workout- like burn.
I jerked off twice yesterday and fucked Susie three times, my cock has serious cumburn.
by Ed O'Neill February 28, 2009
 
3.
When a man ejaculates so many times he gets a work out burn, but within his cock.
Yo man I had so much sex last night i got cumburn today.
by Eddie O'Neill December 21, 2008