All the time. Sho looks a little uninterested/uncomfortable. Tomas loves it - he's a mamma's boy.
I know he really thinks I'm grooming him and he loves to have his face groomed. He tries to get Sho to groom his face all the time and will gladly return the favor.
I just made kissy noises at him and said "come here" - he ran over, hopped in my lap and wanted kisses.
DH will kiss the kitties, too.
Tomas doesn't like it as much when he does it though.
I have an extremely insecure semi feral boy outside who will occasionally give me head butts - I have to be careful with that as he may decide to claw me one day instead.