Pitcher is a slang term that refers to the penetrating partner, usually in a homosexual male context. The reference usually implies that one partner is the pitcher, the penetrating partner, while the other is a catcher (the receiving partner).
More About Pitcher
Pitcher is usually reserved to describe the roles played by the partners in a homosexual male relationship. It is also used in contexts describing anal sex as well as lesbian encounters using a strap on or other toy used for penetration.