main piece 

a woman that a guy dates for the primary purpose of providing his steady source of sex. The woman is almost always unaware that this guy is actively seeking out as many side pieces as possible. See also Main, main bitch, main squeeze.

Dude 1: This club is wack. Its looks like our chances of meeting some fine honeys are pretty slim.
Dude 2: No big deal! I got my main piece waiting for me at home.

main piece by toast455 February 17, 2006

manpiece 

1. The male equivalent of being a slampiece.

2. One who is called upon by a female(sorostitute) for the sole purpose of being sexed upon.

Sorostitute 1: "What are you doing tonight you betch?"

Sorostitute 2: "Calling up my manpiece for a some quality time in the bone zone"

manpiece by partyoverhear June 30, 2011

manpiece 

slang for the male genitalia

He took out his manpiece to show his lady-friend a good time; after a swift quick to his manpiece, Todd doubled over in pain.

manpiece by audioshack June 24, 2005