I'm not sure this is that significant as we (or at least me and a few gf I talked to) fantasize about a lot of things. We think about being with other girls, being picked up at a bar by someone tall dark, and handsome, and many other things.
We can fantasize and it's a fun time. It's when we start thinking and talking to others like these fantasies are somehow true.
Guy's do that about their wives and end up here. Where almost all of us reinforce and encourage the continuation of the fantasy...................and then we blur the lines between the two and ....................that is not good.
Fantasies are fun, but know where they end and don't empose them on the real people around you....