When a chick rubs the area of a man's body where his ball sack connects to his penis with her thumb(s).
by Tom and Mike June 20, 2006
When you first meet a girl and your curious if she is good at going down on you. So you ask her to give your thumb a bj.
boy: (thinking) hmm i wonder how good she is.
boy: hon, can u give me a thumb blow-job? i wanna see how good u are
girl: i might not be good at it, i havent done it in a while.
boy: idc i just wnna see how good u r
girl: ok
. . .
boy: omg ur a fucking pro . . . if only that was my dick!
boy: hon, can u give me a thumb blow-job? i wanna see how good u are
girl: i might not be good at it, i havent done it in a while.
boy: idc i just wnna see how good u r
girl: ok
. . .
boy: omg ur a fucking pro . . . if only that was my dick!
by Nikki Co-co March 28, 2010