"A study of 1,661 U.S. men found...men aroused via oral sex reported larger penis size on average than those who attained erections through fantasizing, Herbenick said.

"We don't know if that means that when men have oral sex that it's more arousing and they get a bigger erection, or means that men who have bigger penises could be getting more oral sex in the first place," Herbenick told LiveScience."

Ah... going for the big one!!!!!