Getting a blow-job while you are benching large amounts of weight. Considered the holy grail of blow jobs. You get huge while getting hige.
A blow flex is where you go into a closet with a girl and she starts to pull your pants down. You looks for someplace to sit and you see a bench. As she starts sucking, you start benching, thus a blow flex.
by Supa Psych Mike June 17, 2010
by Millerxxx11 November 18, 2015