He only started doing it about 2 months ago. I'm hoping that he'll go back to sleeping under the covers once it's not so hot. I have really started trying to get him to get the message, like sottice said. He still sneaks up there at night and licks my forehead sometimes, but if I run him ragged before we go to sleep and keep telling him NO when he starts licking my forehead before we go to sleep, he tends to do it a lot less now. He does sleep on my pillow for a big part of the night, but it was the constant licking that was really keeping me up. Even in my sleep-deprived state, I laugh about it when he wakes me up frantically licking my forehead.