He's performing a Redneck vasectomy
So, a redneck went in and asked a doctor about a vasectomy, but didn't have much money to spend on it. The doctor told him to go home, roll up a magazine and stick a lit firecracker in the end, hold the magazine tube up to his ear and count to 10. Confused, the redneck went home and did as the doctor said. He held the magazine up to his ear and started counting on his fingers.
"1-2-3-4-5... Oh crap!" *places rolled up magazine between his legs and holds up the other hand to continue counting* "...6-7-8..."
It's hard to take a visual joke and put it in writing, but I hope I did it justice.