Jessica continued to slide the tube further into Robert's rectum, much to his protest. Robert knew it was almost over when he felt the latex from Sabrina's glove on the back of his balls. "You're doing great. Just going to look around now." she said. Robert felt her maneuver the tip of the scope around his rectal walls, almost shaking with it as she twisted and turned. Not long after she withdrew the scope and told him he could relax. Robert noted the length of the scope! It had to be at least 10 inches! He had ridden the "Silver Stallion"! "We're almost done here." Sabrina said. Almost? Robert thought. What in the world could be left? "Your form requires that I obtain a sperm sample. Get back up on your hands and knees for me." Robert did as he was told and Sabrina gave him a cup and told him to hold it under his penis. "I'm going to massage your prostate. Just let whatever happens happen." she said. Without warning, she slipped two fingers deep into his rectum. Robert felt her fingers slide along his prostate, and his cock grew even harder. It wasn't long before he could feel the urge "coming". He began to groan with pleasure. "Uh....uhhhh...I'm...." he mumbled as he blew a massive load into the cup. He wouldn't admit it, but it felt great to release all the stimulation from the attention to his rear. Sabrina wiped his crack and looked at the sample "That's a great sample!" she said. "We just have a few more things. Your form requires you to be up to date on all your vaccinations, and you're missing a few boosters. Since we're having to inject so many, these are going to have to go into your bottom." Robert rolled his eyes and sighed. His ass had gone from fuck toy, to pin cushion!