Jeff was irritated... his big moment of sticking it to his dad only lasted a moment, maybe three if you want to be literal. Mike is restored and Jeff gets an organ that will keep his body in excellent shape effortlessly and extend his lifespan, but that doesn't get his father back for his violation. It doesn't repay him for making Jeff think he murdered his dad.
Jeff wanted to really stick it to him, something that would mess with Mike's head the way this situation messed with his. A physical change would be noticed, confronted, and undone... just like before... turning him into an object would have ramifications once he changes back... and Jeff wasn't interested in removing Mike from his life completely.
This left the mental tab and here is where Jeff found more than he anticipated. Fueled by spite, Jeff found himself setting things up that he never would have considered before, let alone using as weapons against his father.
First, Jeff went into the romantic interests section and blacklisted himself not wanting things to get incestuous, only really confusing for his dad. Jeff made his father sexually aroused by humiliation, embarrassment, and shame, pushing the slider up to "extreme" which was just below "instant erection/ejaculation." Jeff also feared that the coming confrontation might push his father over the edge and make things physical, so he also made Mike fall into a submissive role any time Jeff asserted dominance over Mike, also making him sexually aroused when this happens. Jeff set the intensity that Mike would feel if these triggers did push him to orgasm, to be on the level of his first orgasm and he would release 10 times the normal amount of pre and semen. Finally, he set this all up to last a week figuring it will give him time to pick when he wants to confront his dad. Also, the poetic justice of the timeframe was not lost on him.
For security, upon stepping foot in Jeff's room, the Chronivac will immediately fill his intestines and Mike will have 8 seconds to get to the bathroom before he craps all over himself (providing no sexual gratification). It will take 40 minutes of physically exhausting pushing to clear him out and he will be tired afterward. If both feet are in Jeff's room he will instantly become horrified and run out, lasting until he reaches the nearest bathroom, which he will be needing to use... (Jeff found his security system hilarious and set this up to last until removed.)
Jeff activated all he had set up and the week-long countdown began. Going downstairs he caught his dad in the kitchen and needed to test things out. "Oh Dad, you never told me, what were you trying to make happen to us?"
A split second later (after understanding what was being asked and having an emotional response to it), he moaned aloud in sudden pleasure and his heart started racing. Jeff ran over as Mike's face flushed, and Jeff helped his dad to a chair. "Dad, sit down!" Jeff feigned concern. Jeff grabbed him a glass of water and asked, "What happened? How do you feel? What do you feel?"
Mike caught his breath and took a sip, "I'm not sure, I just suddenly felt real..." Mike realized what he was about to say and stopped himself and felt embarrassed for nearly telling his son he was turned on which made him go off like a child having their first orgasm. Mike moaned and writhed and touched his body. Waves of euphoria washed over him, unlike anything he experienced in the last 35 years. He saw that Jeff was watching throughout this experience and was humiliated which only prolonged the experience.
Eventually unable to ejaculate more, his body reached its limit and forced him to come down, Jeff stood there, mouth agape. "I'm fine, check on dinner." Mike managed to say.
Jeff walked off, satisfied that the test worked, and was assured that he could physically dominate if his father tried to attack him once all was revealed.