The process of locking up a girl for the cold winter months to hook up with while giving the girl a false impression of a potential serious relationship. The guy then lets her go when Memorial Day hits, the weather warms up and the sun dresses start coming out.
Guy 1: So how are things going with that girl you've been seeing?
Guy 2: Everything's cool but I got a house in the Hamptons for the summer so we'll see.
Guy 1: I thought this one actually might turn out to be serious. She's just another winter girlfriend huh?