Good one.

I had a experience like that but not shit...blood.

Years ago we had a Chocolate Lab Pup and was doing the same playing with him in the bed.
He still had those razor teeth at the time and took a nip out of one of my nostrils.

There was blood everywhere and my wife and I thought he was bleeding and checked him thouroughly not finding where the blood was from until we looked at each other and she said " holy shit" your nose is bleeding.

I was happy it was snot him, I still have a little chip missing off the side of my nostril.

Good Dog, miss him.

His name was Crinnigan.