Sheesh...I never feel like not having sex. There have been times where partners have wanted me to and I've surrendered and been the better for it. One time I had the flu and so I wasn't really wanting to do it as I felt all sick and disgusting, but when all was said and done I felt the better for it--I got better the next day! So unless I'm absolutely knackered, I'm still going to say yes and be willing. There's only one time I've turned down sex, and that was because I was exhausted, had class early the next morning, and would've had to drive across town to get it...but trust me...I seriously thought about it first.
It wasn't that I didn't want it, it was more than I knew it was better not to.