Well,I know two meanings for pitcher,one used for a baseball player and one is a kind of container for liquids. But I don't get this one(Taken from the movie After Sex (2007)):
Man Number 1:
Still trying to figure out if I liked it.(Sex)
Man Number 2:
Wanna give it another shot?
Man Number 2 [Whispering]:
Maybe you're a pitcher.
In American baseball, a 'pitcher' is someone who throws the ball, and a 'catcher' receives it. In a sexual context, specifically among male gays, a pitcher is he who penetrates and a catcher is he who is penetrated. Often men prefer to be one or the other. Man Number 1 has just been penetrated by Man Number 2, and is not sure if he liked it, and Man Number 2 is suggesting he might prefer to be the penetrator. It is also possible to be a 'benchwarmer' (prepared to be either).
