Bite them and they will let go of that arm faster than you think.lol
Haha, it's all fun and games until he starts to flail his leg a little and knocks your teeth out.
I have a friend who likes to do pressure points while groundfighting, and it's always a bad idea. You don't want me to have a muscle spasm while I'm putting on an armbar. That's how stuff gets really broken.
I once had a friend who insisted that best defense for a triangle was to bite the guys dick. All bad.