a lecherous person who is oblivious to social cues and despite getting repeatedly blown off, lingers trying to be included. If this person was not so annoying, he or she might be attractive.
A sexual partner that the speaker uses strictly for sexual gratification. Several rungs below a fuckbuddy; emotional attachment and/or mutual respect are never afforded to a bangpiece.
Hell no I didn't spend the night... I fucked her and left. That's just my bangpiece, man.