Jeff's dad had just thought of one final change for his knew favorite underwear. In the specific alterations function of the chronivac, he wrote that when jeff was sexually excited he would grow his human boner from the back end of the underwear, facing inward, and be able to feel pleasure from his penis, and even cum! 'This way, I can be fucked by Jeff while he's still my underwear,' thought Jeff's dad.
Jeff heard all of these thoughts and couldn't help but think it was a bit kinky.. "but you won't be able to anything to turn me on dad!," jeff protested in his father's mind. "We'll see about that," said his father hitting the perform changes button and running to his master bedroom.
Jeff's father climed on his bed, ass facing his mirror. Looking back toward the mirror he admired his muscular butt cheeks caressed by Jeff's fabric and he could see his own pleasure in his bearded face looking at his reflection. Jeff could see this all from his father's perspective and it was kind of hot..
His father started to grab his own ass and feel himself through Jeff. Jeff felt his fabric clinging to his father's ass and he could feel his father's boner on the other side. And then it happened, Jeff got his first hard on as a pair of briefs. His dad felt the surprise of his son's teenage boner appear facing his ass.
At first he was just having fun grinding on it, and he could hear Jeff's mental moaning, but he didn't want Jeff to cum yet.. getting his lube from under the bed, he lubed up his sons 6 inch hard on. He guided it into his ass and moaned out loud in pleasure.
By lifting his ass into the air and bringing it down he could drive the boner in and out just a little bit. He did this for just a few minutes before he heard Jeff think, "Dad, I'm gonna cum!" Hearing this his dad stopped humping and felt the teenager's semen inside him, which caused him to moan loudly and cum in Jeff