Ladies why and how does LOVE kill the LUST part of a relationship?

This always happens to me, i can woo them and romance them but they always cry and tell them how good i make them feel and special and then they stop the love making, why? why wont they do it any more? why do they only want to hug and cuddle? what is going on? shouldn't love make her want to be with im psychically? why does love get in the way? how do feelings get in the way of the primal urge? what can be done to push the love aside and focus on the lust?