People are NOT horses and we're much more thin skinned, nor do we groom each other with our teeth.
I don't allow my horses to use their teeth on me, period. Allowing your animals to continue unacceptable behavior is doing them no favors in the long run.
You should be aware that you or your parents are liable if someone else gets hurt because you didn't correct your animal, and now it thinks it's okay to use their teeth on humans.
There's a whole big world out there, and the majority of it is filled with non-horse people who WILL sue if they or their children get hurt by your misbehaving animal.
cute and it is
dangerous, whether or not you want to believe that.