More suggestive, and therefore far more amusing, variation of politically correct, gender-neutered pansexual labels such as S.O. to refer to a sexual partner or boy/girlfriend. See also slamp, piece.
Sorry I haven't come in to work for the past month, i've been busy shagging my new slampiece full-time and couldn't walk straight.
-Bro, I was playin COD on Xbox last night and my number one "SlamPiece" came over and started bobbin me so hard that she knocked the sticks outta my hands."
-Damn did you win?"
-Naw, but it was chill, cause then she made me a sandwich."
Someone, potentially an asshole, who you continuously have hot sex with, but have no attachments. This person is merely used for sex. You may have one or two cute couple pictures with this person on Facebook.
Eric is my slampiece. I call him over at night when I'm bored and I wanna fuck. He can only stay over if I wanna fuckin the morning, too.