Pizza delivery man's unexpected surprise

The scene starts with a pizza delivery guy ringing the doorbell of a house. As he's about to knock, he notices the curtains are slightly open and he can see a couple inside. The girl seems to be giving the guy a blowjob. The delivery guy is shocked but also excited. He quickly drops off the pizza and goes back to his truck to take care of his own needs. He starts masturbating and ends up cumming on the pizza. The scene ends with him going back to the house and knocking on the door, ready to deliver the pizza to the couple.