The more I grow, the clearer I see this concept. Very often we are in relationships (be it a sexual one, or a friendship/family bond) where the person is or behaves good or bad. And you may be doing fantastic things together. But the important question would be, does he make you feel good? Does this person make you feel happy, desirable, intellectually stimulated, ambitious, energized? When you really think about it, very few people make us actually feel good.
Very often guys try their best to make us feel insecure, jealous, conflicted. And people, in general...they wanna make you feel like you don't deserve them. They're missing the point.