bircake
when a female is licking a dudes sweaty man balls, and the sweat from his balls starts to bead up on her top lip. Then she proceeds to lick it off, seductively, while rubbing her temples singing 'happy birthday'.
"Yo, lets go to that party."
"Hell yeah, I'm trying to get that good bircake."
"Hell yeah, I'm trying to get that good bircake."