This happens when he senses you value him more than yourself. It comes out in the things you say and unacceptable behavior you put up with.
In some ways men are grown children. We all are. We have to know where the boundaries are to feel safe. If you've ever been with a man whose a push over you know how unattractive it is.
The most common way this happens is by mothering men because you don't want them to feel bad. Taking care of his feelings sets you up for disappointment because a man who senses you love him more than yourself is headed in the wrong direction.
Men fall in love when they give not when they receive. Read A Life Of Love. A man has to have a plan to love you. If you have the plan you are headed for frustration. If you find yourself in this situation simply step back and stop making the plan.
P.S. Watch How To Know If You Have Chemistry In 30 seconds.
P.P.S. Watch the free videos from http://chemistrytocommitment.com