He humped me in his sleep?!?

ok(im a girl), one night I one night I went to stay the night with one of my guy friends. I couldn't sleep all night. He normally sleeps up against me, so it wasn't weird just normal. I was wearing a tank top and silk pjs i normally wear something more when i sleep with him but thats all i had last minute. I woke up cause he was talking really loud in his sleep. Then he started saying random words. I started talking to him and he answered random things i said lol then aout an hour later i was asleep and woke up to him humping my back and mubbling something lol what does this mean? how can i learn to sleep with it? does this means he likes me or was it just a dream?