Your poor Sparky boy! The penis has a slit at the top, the opening to the urethra where the urine comes out. It isn't a perfectly round hole.
Sounds like he has some razor burn. I gave my Teddy a little razor burn with the clipper once.
I put a little organic coconut oil on it to help it heal. The coconut oil is safe to lick. The back area between the legs can be hard to heal because of the licking access and because when they lie down, the area doesn't get good air circulation.
The next time you have him groomed, tell the groomer about the razor burn and tell the person to be extra careful.
If the rash is bad, I would see the vet.