hoo boy... when Fiance and I were long-distance, we were both incredibly horny! When we got to visit each other for the weekend, anyone who wanted to keep us from immediately having sex -- roommates, family, friends who wanted to see us -- was on the shit list.
Yes, there is phone sex, cyber sex, etc, but it's really not the same as being able to hold someone in your arms. One of the hardest things about adjusting to living together was finding that the intensity isn't really the same: in an LDR where you see each other once every month or two, every time you're alone together you want to go at it, but when you're living together you can be sitting on the couch together at 8 in the evening, both pantsless, and look at him and think "wow, that's a really nice penis" and be perfectly content.
Quite honestly, it's a hard transition because in a long-distance relationship you don't really get the sense of what it's like to really spend time together. Sexual tension lasts much longer and covers for more incompatibility when you're long-distance. You get to spend your time alone in your respective cities fantasizing about each other and talking on the phone about all the things you do when you're apart, and then when you're together it's generally a whirlwind of "sex! oh wait everyone I know wants to see you! Hey I need to show you five of my favorite movies right now! More sex!" In a non-LDR, it's still great to have a good sex life, but you need to be comfortable just hanging out together, too.
I don't think that sex is necessary for a good relationship, but I certainly wouldn't want to be in a long-term relationship with NO sexual component. If people are waiting for marriage to have intercourse, that can be totally healthy and successful, but I can't imagine being in a serious relationship where I didn't have sexual
feelings about my partner, a strong desire to touch and kiss them, etc. But it seems pretty normal for desire to fade in a long marriage after having kids, etc, and I don't think that's necessarily a bad thing, if it's a general loss of interest in sex rather than a loss of interest in *each other.* I hope that my relationship stays hot and frisky for a very long time, but I'd settle for just happy.