After giving someone a Blumpkin, the word "Blumpkin Breathe" is when your mouth smells like the remains of Sperm, Penis, and possibly Feces.
You listen here you little Blumpkin Breathe! (To get someones attention when you know they have been giving the almighty Blumpkin)
Instead of going to pick out Pumpkins, you find someone on the Pumpkin Patch, and convince them to suck your cock while you take a shit on the ground. Around Halloween is the best time to have this very obsene event happen.
Hey Dawg! it's almost Halloween, do you wanna go to the Blumpkin Patch?