The last time he was sleeping next to me on the couch I barely nudged him when repositioning myself and he woke up and bit almost through my hand. Blood spurting. We worried about friends and family coming over. We knew we couldn't give him to anyone because we knew he loved us and if he would bite us, he would bite anyone.
I would check with a professional dog trainer to see if he could be trained out of this behavior.
Do you think it was a dominance issue? What type of training did your dog have? Do you think you were firm with him?
My gosh, it is so disturbing... he loved you, but....why?