This was once revealed to me in a dream.

Somebody is knocking on your door. You get up, wading through your assorted collection of trash on the floor, to answer it. “Hi!” Kronii greets you. You are dumbfounded. How did she get your address? What is she doing here? Why is she here?
“Don't sweat the small stuff.” She sees herself in. “Whoa, you live like this? Crazy. You might wanna... you know, sort this stuff out. This can't possibly be good for your health.” Carefully but deliberately like a cat, she moves though your stuff to your bed. You close the door, unsure of the events that are about to transpire. With nervous excitement mixed with genuine trepidation, you approach the delicate girl sitting on the bed with her legs crossed. You're pitching a tent just looking at her thighs.
With no apparent effort at all, she slams you into the bed. You are paralyzed with most of your muscles frozen in time, only your inner organs and facial muscles still work. Somehow, you feel that can make out your mental state from your expression alone. You suppose you're not as emotionless as you've always thought, now that push comes to shove, quite literally so.
She rips down your pants and roughly shoves aside her panties. At least from their underside, they do not look wet. You don't know much about sex as a virgin, but even to you it seems exceedingly clear that going in dry is going to be a painful exercise for her. She picks up on your puzzled expression. “Oh? You didn't actually think that we'd be having sex, right? You're just a semen dispenser because my bloodline must go on.” She slowly inserts your member. You wish you could feel something down there, but you do not. As soon as it appears to have been fully inserted, she snaps her fingers and gets up. It is oozing with white, sticky liquid that is very familiar to you. You remain frozen on the bed. Everything was over in less than a minute.
“Good job, prejac-kun! You're already done! Now scurry along and forget any of this ever happend. Not that anyone would believe you anyway.” She exits your apartment. The time freeze wears off. Because your cum already left, the ensuing orgasm felt lukewarm, like a participation trophy. Something is just missing without the nut splashing out.

You change your name on YouTube to プリジャック君.