LOL Sky is right for the most part, methinks
I think that if SAers tend to be more 'sex-obsessed', then it is because SAers tend to have less (or far less) opportunity to have sex. The longer one has gone since their last experience, the more important having another such experience becomes in one's mind.
Mooncalf's suggestion is very good

, but it also only goes so far in light of the previous sentence. There are emotional components one will never expereince by oneself.
That men are expected to initiate makes this aspect of SA even harder on men than it is on women.
Jarous: There is quite a big difference between fantasy and memory! At least as big as the difference between masturbation and sex