Top definition
An individual who jacks off in class...generally to his respective teacher. (Abbreviated SB)
1. A: DUDE that guy is totally jacking off in class!!!
B: What do you expect...he's an SB

2. A: What do Semen Boys do?
B: Jack off in class....duh
by The Revealer of the Truth February 09, 2010
Get the mug
Get a semen boy mug for your brother-in-law Callisto.