DON'T DO IT, WHATEVER YOU DO. I'm serious, you will be in so much pain it won't matter how much you like this guy.
Lay down the sex law deep and heavy. If he can't handle it right now then it probably wont' get better when he gets used to seeing you around everyday. Marriage is NOT a breeding ground for romance. In fact, marriage tends to sap romance out of a previously amazing relationship.
Get serious help from a sex counselor. Insist that you both have to be satisfied with the romance thing before getting hitched. Even if you are both in total agreement about sex levels before getting married, it is likely one of you will throw that agreement out the window, just because you don't feel like it anymore. So much can happen to take it away.
Honestly, I absolutely adore my wife and we've had some great times together. She doesn't feel much for me anymore and knowing that the person you've given yourself to doesn't care if you ever share sexual intimacy again is shear agony. I wouldn't not have married if I had known this would happen. Intimate harmony in a relationship is not a extra bonus, it is a requirement.
I would chime in with everyone that this needs to be fixed before you marry. I had a couple of chances to force the issue to be worked on and allowed a I'll try to suffice so 15 years and a daughter later I'm regretting not forcing the issue so we would have gotten counseling then rather than now. If I knew what I was in for I would have stayed single, at least when your alone at night you know whats going to happen and when your not alone you have pretty good idea whats going to happen.
