I get a little bit terrified when I know I'm going to have sex later. When I was younger, it was stomach-churning (literally; I lost 15 pounds from pre-sex puking during my first relationship), but even now, knowing that I'm on my way to fuck someone gives me a weird sense of nervousness.
It's emotional, not cognitive; I'm not afraid of anything in particular. I don't think of bad scenarios, I just feel my stomach knot up and my hands shake. I have to push through that feeling to go ahead with the sex. Once things start, once we're past the first couple kisses, the feeling disappears. But it's almost always there beforehand, no matter how well I know my partner or how many times we've done it.
In Mary Roach's Bonk, there's a compelling description of a young female monkey, in her first heat, making advances to an older dominant male. She's very small and very low-ranking and thus absolutely terrified of both the male and his mate, but she's also experiencing desire for the first time in her life. So she screws up her courage and makes the smallest, subtlest gestures toward him, sitting a little closer to him than usual, sliding a hand slightly toward him, her combination of fear and lust just this side of paralyzing and lust only barely winning out. I can sympathize with that little monkey.
This is the sort of thing that comes to me when I hear stereotypes about women being supremely sexually powerful, about us using our sexuality to pull men's strings--me, freshman year of college, cheerfully taking--or making!--a "hey baby why doncha come over" phone call from my boyfriend, then puking in the bushes because my stomach wouldn't even let me get to a bathroom. And then cleaning myself up and going over anyway, because I just wanted it that bad.
I was a young girl dating an older man and frequently initiating sex with him--shouldn't I have been a minx, a vixen, a little seductress? Shouldn't I have been calmly, almost smugly doling it out to him at my leisure? There's nothing in romance novels and nothing in Cosmo (and wow, definitely nothing in the PUA world) about being so nervous you puke and so horny you rinse out your mouth and fuck him anyway.
It wasn't just that relationship. I've got a better handle on my stomach these days, but I still feel the fear every time. It's a quiver through my whole body. I don't know exactly where it comes from, but it has a grip on me from the moment I know I'm having sex soon, to the moment the sex actually starts.
It's all very well to say "women have desire!" But I, at least, have crazy-making desire; I have desire that overpowers fear and common sense and sometimes common decency. My attitude toward sex isn't "I can take it or leave it, so I should get something out of it"--it's "oh God I want it so bad I can't stand it." I want it so bad that I shake, and embrace a man with shaking arms, and at least I have the goddamn insight not to imagine that he's some stone-souled cruel overlord doing this to me deliberately.