Lowers his arousal back down

Cynthia makes a face as she kicks off the pajama pants from around her ankles and picks them up.
"Can you throw these in the laundry?" she asks, "I need to get cleaned up."
Mark nods, still a little dazed and dumbstruck from his premature orgasm, and takes the pants from her. As he heads towards the laundry, she takes her phone out of her pocket and lowers his arousal. As she walks to the bathroom, she applies several other settings to Mark's cock, disabling his ability to get hard, have an orgasm, and ejaculate. After all, she didn't want him having sex with anyone else, or even masturbating. No, from now on he'd get no relief from anyone but her, and when he did get it from her he'd perform so poorly he'd wish he hadn't. She smiles as she put down her phone, stripped off and started the shower. As she waits for the shower to warm up, she reaches down to her pussy, still unbelievably wet from the thrill of using the app. She puts her leg up on the edge of the bathtub and begins to masturbate in earnest, rubbing her clit eagerly as fantasizes about Mark seeing her like this sometime and knowing that it was his inadequacy which led her to it. She gasps as she reaches an orgasm at the thought of him hanging his head in shame.

As she showers, washing her cheating husband's cum off of her body, she thinks about the logistics of how she'll be able to properly pull off her ****. The main problem was that she wasn't always around Mark, so there would be points throughout the day where he'd be outside of proximity for her to control his cock with her phone. What she needs is to somehow make it so that her phone is always near Mark, but how? Finishing showering, she googles "iCock app long distance" to see if there's a solution, and there is! Kind of, anyway. Apparently, if you have a second phone with the same Apple ID, the second phone will also auto-install the iCock app, allowing users to control cocks in the vicinity of both phones from either one. It's perfect. She'll go to the mall tomorrow on her lunch break, get a secret phone, and hide it in Mark's car so that it'll travel around with him. No, he might park the car in a garage somewhere and walk outside of vicinity, she thinks to herself, and anyway, what if he goes out drinking? He always leaves the car at home. That's when she remembers Mark's backpack. Mark is one of those people who prides himself on being prepared. He never goes anywhere without his backpack, which always contains, among other things, a first-aid kit. This, Cynthia decides, is the optimal hiding place.

She gets dressed in fresh pajamas and heads back out to the kitchen. Mark has cleaned up the rest of his cum from the tiles. Cynthia smiles as she microwaves the bowl of spaghetti she'd put down in order for him to fuck her. Mark is watching TV, having already eaten. She sits down beside him with her dinner and notices that he still looks a little embarrassed at his poor performance.
"It really is okay," she tells him gently, "I wasn't even that horny."
"I know, I know, " he says, as though he didn't notice how wet she was in the five seconds he spent inside of her. Cynthia notes to herself that despite him clearly not having satisfied her, he didn't offer to go down on her, or finger her, or do anything to try and help her cum. His shame wasn't from failing to please her, it was from failing to live up to the image in his head of himself as being oh so sexually proficient. An image which, with the help of the iCock app, Cynthia is going to completely destroy.

The next day, she goes to the mall, buys what she knows is the cheapest iPhone which is still capable of running iCock, and sets it up.