As a reader, I'm reading a story for its sex. I'm more interested in the plot. If it happens to be there, it's no big deal to me.
I read Graeme and Wibby's stories and have enjoyed everything that I've read of theirs. Another author that I read, Jamie, doesn't include sex in his story. He has eluded to it, but he's never gotten descriptive with it and he won't either.
A story can be interesting without the sex and I can agree, it can help a story sometimes. Or it can detract from it.
And I've said this before. If I want something with explicit sex in it, I'll go to Nifty.