It was still dark outside and the sun had yet to rise, but dawn was slowly creeping in when Anon awoke to his throbbing member inside of Yuki’s back. No wonder he dreamt a series of wild and sultry sexual fantasies throughout the night. He had been aroused all night by her subtle movements, and the heat radiating off of her body. He couldn't help himself from wanting to make love with her again that morning.

Quickly his arousal was spiralling out of control and thoughts of waking up Yuki for a second round were becoming more and more tempting. He knew he should stop, but the temptation to just thrust a little bit further into her beckoned him. It would feel too good to resist. He held his breath as he eased himself in ever so gently, feeling her warmth envelope him as she groaned softly in her sleep.

He pushed forward, and pulled back, his movements gradually increased in intensity as he stayed deep inside her ass. The pleasure was overwhelming - her cute buttcheeks were both soft and tight at the same time. His passion growing with every thrust, he continued for a while in absolute bliss before she started to move. She shifted from side to side, arching her back as their rhythms combined and the pleasure intensified even further.

But as the morning was slowly beginning to break and the sun began to rise, their roommates were starting to stirr in their sleep. Anon needed to move quicker if he wanted to finish what he had set out to do.

Unfortunately he only managed to push into Yuki a few more times, not enough to reach the ultimate climax before her sister Mio would get up. Anon had to abandon his movements yet again, while Mio descended on the ladder from her bunk bed. But the feeling of his dick being logged into Yuki's ass while her sister was nearby gave him an extra level of exhilaration.

Yuki remained as still as a stone beneath the blanket, but in the morning's illumination it would now be possible to spot her with a watchful eye.

Anon found a thrill in the increased risk of discovery. Perhaps it was a lingering effect of the alcohol from earlier in the night. Before, when Mio had gotten up, he had kept his eyes shut and pretended to be sleeping. This time, however, he dared to open them and take a look at her as she went about looking for her phone, that was connected to a charger close to the floor of their cabin. His heart raced as she moved around the room unaware that he was watching her every move.

But he was starting to get confused. The young woman he was looking at didn't seem the same as the Mio he remembered. He was certain that Mio had dyed blonde hair. But this girl definitely had natural black hair.

Was this actually Yuki walking around? He racked his brain to recall the specifics of last night, unsure if he was remembering correctly or if he had been confusing the two sisters.

And if this was indeed Yuki, then who was his dick currently penetrating under the blankets? Was he actually fucking her married sister Mio?

He was so confused, all night he thought he was engaging with Yuki. But here was Yuki totally unaware of what was happening. Then, the girl who he now believed was actually Yuki left the cabin.

The girl beneath the blankets must have heard the door close and feel secure again, prompting her to start grinding against him again. She moved her hips sensually and her tight ass felt amazing as it caressed his shaft. The thrill of not knowing who was beneath the blankets only added to his pleasure. She pushed further against him, her breathing becoming heavier.

She whispered softly in Japanese again, and this time Anon could make out the words 'ass never again' and 'enjoy the last time'.

Anon was almost to his peak as the intensity increased with her every thrust. He was in a state of pure euphoria, completely helpless to halt her passionate movements.

Maybe he should have looked more closely at who was actually under the blankets. He just couldn't believe it was Mio; she had seemed so happy and flirty with her husband Haruto the night before. They had made such a picture-perfect couple.

But he was certain it wasn't Yuki he was with, as he distinctly recalled seeing her leave the room just minutes ago. His senses overwhelmed by the rhythmic grinding of the girl's ass on his dick, it became increasingly difficult for him to focus his mind on anything else. The sensations that coursed through his body made it near impossible to form any coherent thoughts. She was pushing him closer and closer to the brink of pleasure with each passing second, flooding his system with a rush of endorphins that left him feeling disoriented and enthralled at once.

Haruto wakes up

But at that moment, he heard an unmistakable loud yawn coming from Haruto's bed. He looked over and saw Haruto turning. The girl beneath the blankets had also heard the noise and was clearly trying to remain undetected, but she didn't stop what she was doing. She cautiously continued her movements, slower and more careful then before, but still drawing him in very deep.

Haruto had now awoken with a jolt, his cheerful voice ringing out in the room as he joyfully exclaimed an enthusiastic “Ohayou!” As his eyes adjusted to the morning light, they soon fell upon Anon. His face lighting up in a wide smile, Haruto added a cheery “Good Morning!” towards Anon.

As soon as the first words came out of Haruto’s mouth, the girl underneath Anon’s blanket stopped moving and froze in place. Anon’s dick still twitching deep inside her.

When Haruto added the “Good Morning”, Anon could feel the girl trembling and stiffening in response. It was clear that hearing Haruto’s voice had a strong impact on her.

But Haruto left him little time to process the situation, engaging Anon in conversation almost immediately. The resulting small-talk was mostly inconsequential and insignificant, but of course Anon had a very hard time concentrating or responding as his manhood was still embedded deep inside of the girl's backside.

To make matters even worse, Anon glimpsed what he had feared the most- a long tendril of white hair peeking out from under the sheets. There was no doubt about it; he had just been involved in sexual intercourse with Mio, Haruto's lovely wife.

But it was already too late to stop. Mio's trembling fear, her clenching her sphincters muscles, gave him the final push over the edge. His manhood erupted within her, injecting powerful spurts of semen into her butt. He could feel how Mio quivered and her physique rippled around his twitching member.

Haruto had posed a question to Anon, his gaze never leaving him, awaiting an answer. But Anon couldn't manage to speak, as at the very moment his dick was still ejaculating inside of Haruto’s wife. Haruto repeated his query once more, but all that Anon could muster up was an agonized groan in response. His breathing had become labored and his hands trembled as he realized how close he was to revealing exactly what was going on below the sheets with Mio.

Haruto looked perplexed for a moment, but then proceeded to burst into laughter as he declared that Anon was too hungover and should get some more rest. With that, Haruto stood up and exited the room, presumably heading towards the bathroom just like Yuki did.

As he left, Anon felt a huge sense of relief wash over him. After all this time, it was the first time they had been alone in a room together. He could still feel his dick twitching inside of Mio as the aftershocks of pleasure continued, and now that they were undisturbed he could focus fully on his orgasm.

Mio was still trembling, her breath hitching as she tried to contain it. Taking her hands, she pressed them up against her face and covered her eyes, as if she was making an attempt to conceal herself from the world. As if she didn’t want to face the truth.

Then, slowly, hesitantly she rotated her head around and her eyes widened with shock as they met his gaze.

Anon was watching as the corner of her lips began to quiver and his gaze followed her eyes as they darted around the room. She was clearly realizing the severity of her mistake when she confirmed it was him lying there with her and not her husband. And then came the sound, it was almost a whimper but it was enough for Anon to recognize what she had said - a panicked and strained “no” which reverberated through the air.

Anon felt completely lost, not knowing what to do or say. His penis, however, was seemingly operating of its own accord as it stirred once again at this most inopportune moment. This time his member twitched with far more intensity than before and it made one last involuntary spasm before releasing the remaining semen deep into her clenching bottom. Mio shouting out another “no, no” in response.