In the situation I'm in now, my female friends tell me I'm the "back burner", "safety net", "back up plan" for this girl who's been leading me on. I want to know what a "back up plan" really is, and why so many girls do it? Like what do they expect from "the safety net", what are they used for, what are the possibilities for a guy who's a safety net, what justification or moral reason would a girl do that to a guy? It just seems to me a lot of girls admit to doing it, but they all don't see it as such a terrible thing (and these girls are usually nice people) so what's the deal?