I don’t think we fully understand lust. We compare it to the sexual desire felt among all of mankind. The desire to become one physically with the man that has aroused these senses. But sexual desire is a natural occurrence shared by all of mankind. Lust in definition then is not sexual desire alone, but it is uncontrollable sexual desire. People who cannot control themselves will only end up in the least desirable situations. In relation to lustful commitments, relationships that are built upon an uncontrollable sexual desire: The physicality of all things can only go so far. In time, pure desire without genuine love will burn out into an unrecognizable flame; it will rust along the outlines of passionate flesh, and it will mock the remainder of your dedication, which is built upon nothing but the chemistry of a kiss. Irritation will then ensue as you come to find that you share nothing in common but the power of sexual desire, the devouring of the others flesh; the tingling of a single touch. But this euphoric feeling is only temporary, and so this lustful commitment becomes an easy addiction to the release of prolactin, and the climax will be the only thing that you share.
My advice is simple: Make sure that when you marry him, it’s because you fell in love with his mind. Consider yourself warned.
The PBS Blog 