Dog question.

Can't find anything on Google. A few tines today after my 6 month old puppy has been asleep I notice that the side of his face is soaking wet. Its so wet I thought he had peed on himself in his sleep. But it has now happened three times. I touched it earlier and it felt kinda slick. But I had bathed him and thought I didn't rinse his little beard good but now it has happened again and I'm getting concerned. Does anyone know what it could be?