Much bigger than Tom expected.

As the treatment continued, Tom could see Sarah's dick growing day after day, but it was growing much faster than he expected. He remembered when Sarah had her first erection, her dick was just over half the size of his, and he hoped that by the end they would both be roughly the same size, but that wasn't how it was happening. Just five days after her first erection, Sarah's dick was already the same size as his and, according to the prediction, it would still grow for at least another 10 days. Impressed by imagining his wife with a dick bigger than his, at the same time he was scared by the expectation of how big it could get if it continued growing at this rate.

"Hey honey, I was thinking and I believe it's about time you let me fuck your ass." Sarah said that day as she slowly stroked her dick through her clothes.

"You fuck me right? Well.... I don't know if it will happen." Tom said, nervous because he had forgotten about that possibility

"How can it not happen? I'm making the sacrifice of letting you fuck your bad ass, now you come with this story that won't let me fuck yours." Sarah said

Tom sighed, seeing that he would have to face this, so he said "That's not what I meant. It's not that I won't let you fuck my ass, it's just that I'm a little scared about it. I've never been on the receiving end and it makes me nervous just thinking about it."

"So that's it, you're afraid I'll end up hurting you. Don't worry, I promise to be gentle, at least until you get used to it." Sarah said

Without any arguments, Tom gave up, thinking that this was just a matter of time and that it was better to start as soon as possible, so he would get used to her size while Sarah's dick got bigger and bigger. With that he surrendered and, for the first time, Sarah fucked his ass.

Over the next few days, Sarah's dick continued to grow rapidly and, after four more days, it was almost 10 inches long and Tom's plan to get used to it hadn't worked, that dick was simply too big to go in his ass and it didn't enter anymore.

Concerned, Tom needed to solve this problem, and one of his options was to use the coin to undo everything.