Women actually don't sleep with most men they're attracted to because they would feel slutty or cheap. Her feeling slutty or cheap isn't about an "Oh, I put out on a first date," thing. It's not about number of dates, hours spent together, or how many dinners you bought her. Feeling slutty is about sleeping with a man who doesn't care about her or who hasn’t connected with her. If she doesn't trust you or isn't 100% convinced that you really like her and care about her, then she's not going to do it. And if she does, then she’ll regret it and feel dirty.