This makes you a great kisser, for example. However, you're not necessarily a devoted partner, and this can get you in trouble. You like girl. Girl likes you. You tell girl that you like her, but it's not too serious.
Girl says okay.
You're ready to move on. Girl gets pissed and calls you inconsiderate. But you're not really. You just don't communicate that well. Playing the part of Playboy isn't easy.