....one night last year i was having a dream about my sister being really pissed at me because i was in love with her boyfriend. she got really mad and slaped me. I woke up at that same moment and felt the pain of someone who had actualy slaped me, but no one was there. I remeber getting out of bed and walking to the light switch. i turned on the lights and went to my mirror and there was a big white hand mark on my check. I didn't get a good night's sleep for a week.
Maybe she was pissed at you and you just thought you were dreaming, but you were actually in a fucked up state of half-consciousness.