The one thing that stopped Tanjirou from being consumed by guilt and shame was the fact that Nezuko seemed to be doing a lot better after what they did. While she still wasn't acting quite like herself (or rather, her regular demon-self), her heat didn't seem to be controlling her anymore. Tanjirou told the others her cycle was probably ending and that was why she was no longer in pain. He wasn't sure if they really had believed it, or if they knew exactly what he had done to help her and simply didn't say anything about it because it was convenient for everyone.

He didn't care. All that mattered was that Nezuko was okay now and didn't seem to have any guilt or resentment. In fact, she looked grateful. Still, Tanjirou had decided that events of that night would never happen again. He didn't go to his sister room when everyone else was asleep, even though he was aching to do so. What they did was necessary, but he'd use the time until her next heat to find another way.

His sister, however, didn't agree to that. Unlike the previous day, Nezuko wasn't happy. She was acting grumpy and bratty, something she had never done before, not even as a little kid. Obviously that shocked Tanjirou, especially since she seemed to be angry with him, instead of being her usual sweet, pleasant self. He desperately wanted to know what he had done to upset her.

The answer came crashing down on him when he decided to bathe. His little sister simply showed up, looking furious.

"N-Nezuko?" Tanjirou covered himself up with a towel, cheeks burning red. He knew it was a bit stupid to be embarrassed that she saw him naked, but he couldn't help it.

That night never happened. Forget it. Forget all of it.

"Did I do something wrong?" he asked, walking towards her, ignoring his own discomfort. His heart sunk as he saw her anger being replaced by sorrow for just a second, which then gave way to resentment. There was no doubt in his mind anymore had hurt her somehow and he needed to make things right "Tell me what I have to do to fix this, Nezuko" he asked, forgetting that she could no longer verbally explain her thoughts since she wasn't human anymore.

Tanjirou saw her shiver as he cupped her cheek and caressed her face. Before he could pull away, she threw away her muzzle and kissed him passionately. His brain stopped working for a moment, and he kissed back, wrapping his arms around her and keeping her as close to him as possible, hands roaming her body and tongue exploring her mouth.

Suddenly, he was brought back to reality and realized what he was doing. He broke the kiss and gently pushed her away.

"No, no, no, we can't"

Nezuko simply used her demon strength to keep in place and pressed her lips against his again, practically ripping the towel away then started pushing him to the bath. Tanjirou just awkwardly fell into it.

He watched her undress and get in the water with him. Her beauty was more surreal and otherworldly than anything he had ever seen or experienced in his life. She kissed him and cuddled up next to him. Tanjirou awkwardly patted her on the head.

"Nezuko, don't get me wrong, but we really shouldn't be doing this"

She ignored him and started kissed his chest while gently running her nails through his stomach "Tanjirou... Tanjirou..." she whispered as she pressed her lips to his skin.

He sighed and gave in, leaning back on the tub, rubbing small circles on his sister's back. Nezuko smiled and pulled him in for another kiss. This time, Tanjirou didn't fight her at all - he couldn't, not after that night, not after how he felt when he was having sex with her. The only reason why he had ever fought against his feelings for her was his fear over her reaction.

And now she was offering herself up to him.

Tanjirou grabbed her hips, pulling her to his lap, and Nezuko's arms laced his neck. Gently, he inserted his cock into her, making them both moan. He thrusted slowly as they made out, ignoring the voice in the back of his head telling him that people would get suspicious if they took too long. He wanted to enjoy this moment, and any others he'd have with her.

He cupped and squeezed her breasts, then moved his head lower to suck on them, feeling delighted as his sister giggled, gently running her nails through his scalp. She seemed so happy and was looking at him to sweetly... he would never be able to give up on that.

Nezuko started sucking and gently nipping at his neck, and Tanjirou could hear panting and sighing in content as he poured a little water on her back. One of his sister's hands were in his hair, playing with it, while the other was on his back. She was careful not to hurt him with her claw-like nails.

As they started moving just a little faster, he pulled her in for one more passionate kiss, then licked her neck as she threw her head back, moaning. He brought a hand to her clit, smirking as it made her squirm in pleasure. It didn't take long for her to climax, and Tanjirou got his own release a few instants after. He stayed inside her until he went completely soft.

The two of them stayed in the bathroom for a long while, washing up and giving each other massages. Once they were done, Tanjirou dried and brushed Nezuko's hair, earning himself a hug and a kiss.

They sneaked out of the bathroom and went to their own bedrooms - but Tanjirou was so happy, he wouldn't have even cared if anyone saw them leaving.

Or if anyone would see him sneaking into her bedroom later.