12 week old puppy peeing in sleep

My puppy has been at my house for almost three weeks now, the puppy sleeps in my bed with me and our other dog. The past week, the puppy has flipped over onto his back, passed out fast asleep, and started peeing all over himself, on his belly, on the bed, and my pillows (😍my fault for having him in the bed I know) dead asleep. Tonight I woke up to the smell of urine and I look over and this little shite is belly up fast asleep peeing like a water fountain all over himself. This is my 4th puppy- in three years… I’ve never seen this before. Has anyone else had this experience and any tips or tricks???