When you ejaculate and instead of shooting outwards, it just overflows like a volcano and runs down your dick.
ZOMG!! look honey its a cumcano
by Big Taran October 31, 2010
When masturbating after ejaculation when the cum fills your belly button. You squeeze your belly button causing a cumcano
Hey man after jerkin it last night I had a huge cumcano
by dr. cuddles February 03, 2011