It seems like “side chicks” are all the rage these days.
I’ve never been interested in being someone’s “second choice,” but I guess some girls like having a guy without the commitment. Or maybe they think he’ll eventually dump the “public” or “#1” girl for her one day. I can guarantee this never happens, though.
Anyways, here’s Urban Dictionary’s definition of a “side chick”:
Sally: No Kimmy! Josh is dating Laura. Tina is just his sidechick.