My 10 month old thinks it's hoot to bite me..help!

CBlok

He got his two first teeth (bottom) in about 2 weeks ago and has since started full on biting me when he nurses. The first time it happened, and every time since then, I say "no!" and stop nursing, but he just cracks up in a very "evil scientist" type laugh...he doesn't mind that I stop the nursing session or anything...not sure what to do...every time I start to pull my puppies out my stomach clenches in fear...any suggestions?