Marriage is a serious matter for Muslims. Since it decides who stays with you for the rest of your life and it also affects your hereafter to a great extent.
If a Christian guy is ready to convert to Islam just for fulfilling his sexual desires, lust and worldly enjoyment, his faith will not last long. After a particular point of time in life when his desires end, his faith will also vanish. Therefore it is very dangerous to marry such a guy.
Marry a Muslim man who can be a better spiritual guide and support to you, the one who fears ALLAH and is conscious about his Islamic faith, the one who prefers religion over his self-desires.
ALLAH knows the best.