C.F.
Hi K.,
I'm not sure if the problem is just with biting, or with sucking harder than normal. If it's biting, though, I've been through that, and here's what I did. My kids would sometimes bite and not let go, and when they did, I would immediately plug their nose. That would break the latch, and surprise them just enough to get them to not do it too much. Other than that, the only thing I can suggest if you think he's trying to relieve teething pain is rub his gums real hard with your finger prior to letting him latch on, which might give him enough relief to not use you as a teether! Good luck.