Probably my biggest continuous revelation when it comes to sex is that sexual pleasure is happiness.
Going in to it, I always thought that sex (or later, perverted/promiscuous/etc. sex) was a dirty pleasure, something like binge eating or cutting yourself--the fulfillment of a physical compulsion but marred with shame and guilt. Something that feels good, but you don't feel good about.
But it turns out, at least for me, that it's simple joy. Like rollercoasters, like sunshine, like puppies. Getting spanked and fucked by near-strangers makes me smile and sparkle and laugh. Other than a little performance anxiety and occasional fear of getting "caught," my emotions about it are positive and surprisingly uncomplicated. It's fun!
Not for everyone, not always even for me. But at its root, when there are no complications, sex is joy.
I've been singing all day.