Scientific research shows that after s*x, the body produces a hormone oxytocin which makes you more attached to the person you just had s*x with. Unfortunately, for women the period is longer- about 2 weeks after having s*x that hormone can still keep you attached to the guy. And for guys- it’s a shorter period of only 48 hours or so…So, you see, after s*x you will be more attached to the guy than the guy will be attached to you. So make sure that he is the right guy in advance, before you start having s*x with him.
If the guy disrespects you, comments about other women how hot she is and so on, then he obviously is not interested in a relationship with you or he may be not concerned about your feelings. You don’t want to be with an inconsiderate guy.