It took a few days before Brian could admit, even to himself, what he was feeling when he looked at Catherine's new canine form. When he was feeding her (real meat dishes, not kibble), or taking her out for a walk, he would feel a hot flush of arousal here, an unwanted erection there. At first, he insisted firmly to himself that he was just thinking of her as a human, and that was what had turned him on. But that got harder to believe every time it happened. The mental image of the woman he knew so well was attractive, yes, and he tried to redirect his thoughts to that image whenever he noticed his penis getting hard. But he couldn't distract himself from the fact that he was aroused before he stopped thinking of her as a dog.
Brian had been in this long-distance relationship for long enough that he was used to getting most of his pleasure alone. Phone sex was great, on the rare occasions that Catherine could get enough privacy and a decent satellite linkup for long enough to make it happen. But the rest of the time, he was a frequent masturbator. He had always felt good about the fact that he usually thought about her and not some other woman - she really was the hottest person in the world, as far as he was concerned. Bringing her home as a simple animal changed the way he pleasured himself, but not in the way he expected. He struggled to focus on the image of her human form, because that thought always led back to the reality of what had happened to her and where she was now (usually just in the next room). Rather than forcing him to think about other women, though, his brain was stuck on her doggy self right up until he finished into a tissue. And when he did try to push himself out of that mental rut and think about some Hollywood actress or something, he started to idly wonder what it would look like if she became a dog, too.
Denial soon gave way to shame. Once Brian could no longer ignore his sense of attraction, it was hard for him to even look at Catherine. That was only resolved with the arrival of the custom-built keyboard he had ordered. "Keyboard" was a generous term here - it was 26 big, round buttons (and a space bar) that were wired together and hooked up to a display - but it was the only thing he could find online that seemed like it could be operated with paws. And one of the first messages Catherine laboriously typed out with it - after "I LOVE YOU" and a lot of profuse thanks for everything - simply read "ITS OKAY".
"What?" said Brian, desperately hoping she hadn't picked up on the erection he was currently sporting.
"I CAN SMELL IT ON YOU", Catherine pecked out with surprising dexterity. She was getting the hang of this - all of this. "YOU WANT SEX" - in the absence of any punctuation marks, a double tap on the space bar ended each message. "AND ITS OKAY". Satisfied with her work, Catherine looked up at her husband expectantly.
"Really?", Brian said, not entirely sure how to take that. "You mean you still want to..." He trailed off there, not willing to be as cavalier with his words as she was.
Catherine simply nodded in response.
"Right now?"
Her tail started wagging at that. Brian couldn't help but crack a smile at the sight. Of course this was going to be okay. They loved each other. It was totally consensual. Who was going to tell a married couple what they could and couldn't do in the privacy of their own home? And it didn't matter what anyone else thought - there was no way they were ever going to find out, right? Yeah, that's right, Brian said to himself as the pair of them retreated to the bedroom. That sort of confidence didn't come naturally to him, but this was hardly the first time Catherine had taken charge and filled him with some resolve. He couldn't hold back a grin when the word "filling" crossed his mind.
Catherine was quick to get into position, although it wasn't quite the position that Brian had been imagining in the darkest recesses of his mind. Instead of presenting her rear end to him, she laid on her back and splayed all four legs up in the air in the most inviting fashion she could. Brian was almost a little disappointed that this wasn't playing out exactly as it did in his fantasies, but he shook that thought away immediately as he approached his wife on the bed. Having her subtly show the last remaining part of her humanity like this was better than just having sex with a dog... right? He wasn't sure what he wanted out of this, he just knew that all of it was overwhelming his mind and he needed to do something about it right now.
Under normal circumstances, some sort of foreplay would have been in order right now, but Brian wasn't worried about that right now. He was impatient, and he had to assume that Catherine probably felt the same way. He wasted no time in removing just enough of his clothing to let his dick swing out freely. It was hard, painfully so, as though their strange life together in the past few days had all been just one big tease. Before he could question what he was doing, before he could get self-conscious about it, he lowered himself inward and stuck it into what was, by all outward appearances, a dog's vagina.
Instantly, a wave of intense pleasure passed through him, and the fervent snarling and yipping that he heard coming from below told him that he wasn't the only one. He buried his face and his arms deep into Catherine's soft, thick fur as he thrusted, trying to have as much of this experience and of her as he could. He hadn't been close enough before now to really get a deep breath of his wife's new scent, and it only enhanced everything about what he was feeling.
Another jolt tickled the inside of Brian's head, and then it was all over as quickly as it had started. Something told him not to pull out right away, to let his seed trickle all the way down inside her first, and he didn't question that instinct. When he did start to extricate himself, a sense of post-nut clarity, a creeping shame about what he had just done started to work its way back into his mind once again. But those thoughts were only just getting a foothold when Catherine looked up and met his worried gaze. Her look of complete satisfaction, such a human expression on an animal's face, told him that - one way or another - it was all going to be okay.