This seems to be a common theme on this site - while my situation is not as serious as some of the posts that I read, I want to prevent it from becoming unbearable.

My fiancé and I have known each other for 5 years. We were originally friends; both involved in other relationships. I moved away to graduate school, and we started a long distance relationship when I had a year remaining. I briefly moved to his area for a training fellowship, and our visits went from 1x every 4 weeks to every weekend. Our sex life has always been great - but since I've been closer to him, he doesn't seem quite as interested in sex. He is very loving, touches me often, kisses me, talks about sex... but when it comes time to actually do the proverbial deed - it just doesn't happen. No erectile dysfunction - he just kind of turns off when I try to seduce him. We still do have sex, but I am a very sexual person - he knows this... and it just isn't enough for me.

When I bring up the subject, he says that he finds me very sexy (as he should), that the sex is great, and that he just doesn't want me to think that he is only about the sex in the relationship. He claims to be in love with me, and we obviously plan to get married. Is he being serious? Or is he just not attracted to me? Will this pattern continue and worsen over time? I really don't want to go through my 30s undersexed and overworked.

You need to fight ways to make him feel comfortable. Talking to him about it just won't do it, maybe do something creative and unexpected. A nice backrub or something. Just be patient.

Maybe your drive is a lot more than his, so I suggest some real talking before you get married. If this is an issue now then it will be later, so honest communication is the key to figuring out how you both can be satisfied. Be honest and tell him you need more sex and if he can't accommodate you find out why, and work out a reasonable compromise where you both win. If he cannot at least discuss this, then that is something to think about isn't it?