Blake Shelton: I Got a Mouthful of Gwen Stefani

This thing might be real after all ...

Blake Shelton playfully gnawed at Gwen Stefani while "The Voice" was on a commercial break Monday night.

Officially, for all the doubters, the TV sweeps period ended 12 days ago -- so maybe they're not together just for ratings.

Then again, for you true believers ... there is still a 'Voice' finale to promote.