Licking a face lol

Is it normal to lick your mom's face and your mom also licks your face? It's more of an ew gross thing that my mom and I do to each other. lol It's funny to us, but others seem to not understand that... It's so the other person wipes their check off and is all -_- why you do that to me? A silly way to play fight, where is not serious... Others don't seem to understand...