How do I get him back?

My boyfriend broke up with me last Friday. He said he never felt the "fireworks" and "lightning" in our relationship. We dated for about 4 months and he says he continued all this time because of my excellent qualities (including the fact that he feels I will be a good mom). He said I am the best person he has ever known but doesn't think we are sexually compatible. We are compatible in every other way, have great conversations and his entire family loved me in the few meetings we had.

We had planned a trip to Miami for the coming weekend and are still going as friends. I want to spark the fire (without him knowing) so he would want to get back together. What can I do?

P.S. I feel the reason he doesn't feel as much passion is my not-so-perfect figure. I am a size 6 and am not really overweight. But I have some belly fat. (It's not that he has the perfect body. He is actually too skinny.) I know I have the ability to turn heads with a little effort and will dress up very well during the trip, but I want to light some "fire" with my actions and words. Pleeeeeeease advice me. I am 24, he is 31.