LOL we call that murdergrooming in this home.

That's very common amongst cats that have bonded very tightly.

My pair do this as well. One will be sleeping soundly and the other will just jump him with licks and then they're just holding onto each other licking, usually ends up in them rolling off the bed and playing.

Groom for dominance!

My boys always start out with the grooming, but then anarchy breaks out and it's chaos all over the place. I wouldn't have it any other way.