"We… We should really stop doing this… I don't think Master appreciates us continuously sneaking into their room and watching them sleep…"

It was around 1 in the morning at Chaldea, the staff have long since turned in for the evening as have many servants, several still up not needing to sleep at all. On this particular night, Hassan of Serenity, Kiyohime, and Minamoto no Raikou together decided to engage in one of their favorite pastimes in chaldea, sneaking into Master's room through the ceiling duct while they sleep. However, on this night, Serenity was against going into master's room.

"Where did this come from all of a sudden? Aren't you the one that wants to feel master's touch no matter what Serenity?" pressed Kiyohime.

"I-I do… I want nothing more to feel their touch… Their skin against mine… But I feel w-we've been doing this for far too long… I mean, we could always interact with them during the day like normal..." she said hesitantly.

"Look, this is one of the only times in the entire day where we can interact with Master uninterrupted by other servants and especially Mash. I swear… That girl is so insistent on keeping us from being extremely close to master, and yet she fails to be courted by either of them just the same." huffed Kiyo.

"Now now Kiyo, Mash may be a tad protective of Master but we can't blame her for that when we are all the same. As a Mother, I want my children to be safe and grow up happy and healthy. Watching them like this allows me to do so where I can easily reach them if someone a miss happens." said Raikou proudly.

"I sometimes wonder what your definition of Mother means. Mainly because a mother wouldn't try to get very sexual with her children… Unless of course… they had that kind of relationship. But I would rather not think about that…"

Serenity only let out a sigh, realizing the two wouldn't listen to her reasoning, granted they never did thanks to their madness. They continued to crawl through the air ducts until Kiyo spotted the grate leading into Gudao & Gudako's room.

"Okay here we are ladies, quietly now…" she whispered to the other two as they crawled closer to it. A faint sound could be heard the closer they got to the grate, Serenity's body tensing up as she was very familiar to the sound, A deep red blush spreading across her face.

"W-W-We should turn back now…!" she whispered a little louder.

"What is your deal Hassan? We're right here, Master is probably just still awake so we can just head on down and tuck this both into bed." said Kiyo as they got closer and closer to the grate, the sounds getting louder and more coherent.

"Mmmph-"

"Huh?"

"What's wrong Kiyo?" asked Raikou.

"I… I hear something muffled coming from Master's room down below. Raikou, help me move this grate so we can see what's going on in there." She moved on ahead of the two and positioned herself around in the duct so Raikou could get access to the grate and help her lift it off quietly. Serenity watched the two pry off the grate, nervous of what their reaction would be once they saw what was transpiring down below. The two finally got the grate off and pulled it over to the side, taking a peek down into Gudao and Gudako's room.

"W-W-What…!?" whispered a shocked Raikou.

"Anchin-sama… what are you doing..!?" said a bewildered and horrified Kiyohime.

Down below, Gudao & Gudako were bare naked on their bed, Gudao thrusting himself in and out of Gudako's womanhood, the latter clenching tightly onto the bed sheets with each second she felt his throbbing member pushing back and forth inside of her. Gudao held on tightly to Gudako's hips, her legs spread out wide giving him ample room to thrust into her harder and faster. Sweat dripped and glistened off their bodies as Gudako pulled Gudao down closer to her, the two sharing a deep and sloppy french kiss as Gudao continued pumping himself into her, each thrust much harder than the last.

"N-No… No… This can't be happening…" said Kiyo. She was in pure disbelief that both her masters who she loved dearly, were now making love to each other. She felt her chest tighten up as she watched the two. Raikou was silent the entire time they watched, she felt wrong watching them make love, in her mind it was like watching her own children commit a taboo act. However, something in her felt… a tinge of excitement watching them.

"G-Gudao…! Oh god Gudao…!" Gudako leaned back against him, Gudao holding her in a full nelson, as she cried out his name, feeling his throbbing cock pump into her deeper. Gudao bit down on Gudako's collarbone, while not biting down very hard, hard enough for Gudako to scream out in pure ecstasy. She grinded against Gudao, holding her labia as he plunged deeper inside, Gudao could feel his climax coming, his cock feeling rock hard as they grinded against Gudako's soft walls.

"Gudako..!"

"Gudao..!"

Screaming each others name, Gudao fully ejaculated into Gudako, a rush of semen flowing into her vagina. She felt the tension in her body finally loosen and ease up, leaning back against Gudao as he finally pulled out of her, fresh hot cum flowing out of her vagina. He pulled her in for another kiss, forcing his tongue into her mouth, swirling and twirling his around hers. The two berserker's had seen enough and quickly covered the hole back up with the grate. The three stalkers quickly made their way out of the air ducts going back the way they came, each not saying a word about what they witnessed until they finally made it out into the hallway.

"... M-Master…" whispered Kiyohime. Her mind was racing, trying to register what she witnessed and how to interrupt it.

"K-Kiyo… Please don't be upset…." pleased Serenity as she placed a hand on the berserker's shoulder.

"Upset…. Upset!? Ha… Haha… Hahahaha! He… He was cheating on me with her! But… I love her… but I love him! But she was sleeping with him, and he was sleeping with her! I… I… I don't..!"

Kiyohime was struggling to make sense of the entire situation. She was angry and furious at Gudao for sleeping with someone else, but he was sleeping with someone she loved. She was enraged that Gudako was sleeping with someone else, but it was with someone she loved. She didn't know who her hatred and ire should be turned toward, the one she loved or the one she loved. She began walking off down the hall, her mind confused and conflicted, Serenity & Raikou watching her as she stumbled onward in her confused state.

"S-Should we follow her…? Just to make sure she doesn't… do anything to master?" Serenity asked Raikou.

"No… No we should leave her be. I-I don't think she's in the right mindset right now to do anything…" Raikou was still struggling to come to terms with what she saw as well. She knew deep down that those lustful feelings toward the two masters existed but she deluded herself into believing she had to be a mother to them. However, seeing the two in the moment of pleasure and ecstasy, made those feelings she tried to keep down start to rise back up. She started to feel something wet near her crotch, realizing she was getting aroused thinking about her masters in this manner.

"I-I need to go… I'll speak to you later Serenity!" Raikou quickly ran off toward her room, leaving Serenity there in the dimly lit hallway all by herself. All the Hassan could do was sigh to herself.

"I think I'll just… go stay and keep watch of Master's room… Just in case Kiyo is still angry…"