My first experience with 'sleeping sex' (more on the reason for the quotation marks later) was when my girlfriend was too tired to have sex. i'd thought it would be nice to try something like that, but i definitely wouldn't have sex with a girl without consent, and normally i dont really get into fantasies.
anyway after making out for a while my girlfriend informed me she was tired and didnt want sex. despite this i kept kissing her around her body and rubbing myself up against her. eventually she said "if you keep doing it im just going to play dead" and i said "feel free" or something along the lines.
after i said this immeadietly she laid back and closed her eyes. thinking she was joking i began kissing her and talking. it took about half a minute before i realised either i'd have to stop with the moves or she was going to stay like this.
which is when i got into the fantasy. she was already naked so there wasnt any undressing, but i found myself getting really turned on as i put her arm around the back of my neck and it fell back down right by her side. i started to kiss her on the lips and she didnt budge, i worked apart her lips (on her mouth!) and started licking her tongue and pulled it through her lips. when i stopped her lips had formed into a perfect pout, with her two top teeth showing.
by now i was getting really turned on. i pulled the pillow up that her head was resting on and started to kiss her more vigorously, and started to fuck her very slightly. i presumed at this point she'd either stop me or show some giveaway signs like smiling or opening her eyes. i was wrong.
by then i was into full on fantasy mode. i withdrew and lifted her right leg, kissing it all the way from her toes to her pussy and then back up again. when i finished i let go and it dropped to the bed like a dead weight. i did the same with her left.
i didnt realise how much of a turn-on this was for me but i was about ready to ejaculate by this point, so i started to fuck her. for a few seconds it didnt feel that great but when i saw her head slowly moving up and down the pillow, like she was nodding, i exploded. she obviously knew this as i withdrew, but still didnt move. i went downstairs to clean myself and when i came back up she was still in the same state, and i was still in the fantasy.
i put all her bedclothes on and tucked her into bed and i was sure i could come again. however this time when i asked her to wake up she did and, smiling and giggling. knowing how quickly i had came she jokingly asked if i had a necro fetish, but we discussed it and i think its just the aspect of control, and plus you can focus completely on one certain thing.
i dont do this everytime we have sex but it has grown to be my favourite fantasy, and ive just started looking for porn in this area. i wouldnt enjoy doing it to a real unconscious or sleeping (or dead!) girl, but its an extremely powerful fantasy. sometimes i play dead and let my girlfriend ride on top of me, but even though she says she enjoys it a lot i think im much more into it.