Work Text:
"Today is your day off! I won't let you touch any work!" Heloise had greeted Diluc that morning with an ultimatum.
It wasn’t that unusual for her to worry about his somewhat intense working habits, but this was the first time she had been so direct. Diluc had to admit it was cute the way she cornered him before he got to his study. If the two had shared a bed the previous night, would she have put her arms around him to keep him from getting up?
Finding Heloise’s actions this charming might not have been fair, since it took him a moment to really register that she was serious.
“Was today supposed to be a break?”
Heloise, who was standing in front of the door to Diluc’s study, took one step closer to him. She was careful not to stray too far from the doorway, as he could get around her pretty easily.
“You promised me you’d take a day off this week… and a new week is about to start. If you don’t do it, you’ll be going against your word, Luc.”
There were only a few things in this world that Diluc believed were wholly impossible, saying no to Heloise when she looked at him like that. Still, knowing he was going to say yes did give him a bit of an advantage. If his schedule for the day is going to be free, why not tease her a bit?
Diluc matched his sister’s step forward with one of his own. He leaned down just slightly and let his hand fall to her shoulder.
“Right, and what would you do if I planned on breaking my word?”
The look on Heloise's face made it clear that she hadn't anticipated that response. She blinked and fumbled on her words before speaking. During their lessons, Diluc always told her to plan for the unexpected so at least he could justify this.
"Ah… well, you've always honored your word so I…" Heloise was rocking on her heels until she noticed Diluc's lips lifting in a slight smirk. Once she realized he was just teasing her, Heloise was relieved but she couldn't stop herself from pouting.
Her arms folded over her chest, looking away with a gentle "Hmph!"
Acting was never her strong suit, so pretending to be upset with Diluc doesn't last very long.
"Seriously, Luc… You get so caught up in work sometimes, I wasn't sure if I'd have to tie you down to force you to relax."
"You're welcome to try."
"...Huh?" Heloise looked back up at her brother, face immediately turning red when she fully processed what he just said. Her hands were raised in protest. "Ah! Um! I couldn't do that..!"
"Why not? You don't want to?" The faint smirk still hadn't left Diluc's face.
“I don’t know how to tie knots… in that way-” After speaking, she took a deep breath, trying to calm herself down. The image of Diluc with at least his wrists bound in rope was hard to shake off.
“I suppose I’ll have to teach you sometime then.” Dilic brought his hand to his chin, as if he was considering something much more serious.
Heloise blinked. Her voice was low when she spoke up again, “So I can tie you up?”
“Not just for that. You said you wanted to get more serious about going out and adventuring right? Rope tying is an important skill to have.”
The silence that followed wasn’t awkward or anything like that. Heloise gave her brother’s joke some time to settle before she started to laugh herself. Her hands were resting on her cheeks, which had tinted pink during their exchange.
“Luc! Well… if you're serious, you can teach me about it some other time. Helping me with my training is still working."
She stepped forward, hoping that joke meant he was fully on her side when it came to taking a break. Both of her arms went around his, and she started to lightly tug her brother in the direction of her room.
"You almost made me forget how I was going to treat you, but it's a good thing we have plenty of time!" They were still in the halls, but the way Heloise pressed against Diluc was starting to cross a certain boundary. It was one way to encourage him to follow along without any delay. The two of them did have the whole day with his schedule clear, but Heloise didn't want any of that time to go to waste.
"What do you have planned then, hm?"
"It's ah, a special surprise. You'll have to be patient for just a bit..!"
Once they reached her room (it was a pretty short walk) Heloise practically pushed him through the threshold of the doorway.
--
The surprise was certainly one worth waiting for. Despite his earlier teasing, Diluc didn't really have anything worth brushing off Heloise for.
Though… if there had been something important, Diluc might have found some way to resolve it quickly.
He was sitting on the edge of his sister's bed. Heloise had instructed him to stay there as she undressed in front of him. It didn't take long for her to be completely bare, only wearing the collar he had bought her and black thigh highs.
In most other situations, Diluc's hands would have been on her by now. He knew it wouldn't be right to spoil her plans, so he just settled for imagining himself kissing up her stomach or sliding a hand over the curve of her hips.
While Heloise had been so confident in the hall, it seemed that being almost completely naked while Diluc was fully clothed was getting to her. He quickly noticed the blush coloring her face… and other parts of her.
"You look cute, Hel."
He spoke up, and his words seemed to help Heloise get her nerve back.
"You'll have to come over here to give me this surprise, won't you?" Diluc patted one hand on thigh. Even if she did have something planned, it's nice to follow instructions when he gives them.
Heloise nodded and quickly crossed the short distance between them. Looking down at his lap, she was able to see the tent forming his pants. She put herself between her brother's legs, sitting on her knees.
"I hope this is alright," Heloise spoke up as her hand moved for her brother's zipper. The other rested on his thigh. Diluc nodded in response. His hand threaded into her hair as his cock was freed from the confines of his slacks.
Seeing him in this way, with an encouraging hand on her head had Heloise worked up before she even started. The excitement was certainly mutual. He didn't have a full body view anymore, but Diluc was still appreciating his sister's body as she prepared to service him.
Heloise hadn't kept him waiting for long. She sat up slightly on her knees and moved to press her lips to the tip of Diluc's dick. The hand that had pulled his clothes away now went to the base. He was big enough that couldn't completely wrap her hand around him, but Heloise could start to slowly stroke him. Her lips parted and tongue moved to lightly circle the tip.
The grip of Diluc's hand tightened in Heloise's hair. He didn't want to rush her too much, but he did lightly pull her forward. Eager to please, he saw Heloise inhale and work to take more of him in her mouth.
Her excited sounds were muffled, but the vibrations could be felt as she took him deeper.
"Good girl," Diluc spoke up after sighing. His praise immediately made Heloise whimper, and her response made his dick throb. It was a bit targeted. He knew how much she loved being called that. "I know you can take me all the way."
She bobbed her head to nod in agreement. Heloise had taken half of her brother's dick, but the tip was now pressing against the back of her mouth. With his size, she already knew taking him into her throat would be a requirement. Her own devotion wasn't the only reason she had left the collar on.
For preparation, Heloise inhaled again. Diluc's hand in her hair helped push her forward. The slow pace was needed to avoid gagging but still meet her goal. Her hand had stopped stroking his length as she progressed, but it was now resting on Diluc's hip. A sound close to pure bliss escapes her lips when they're finally pressed to the base of his dick. The collar strains against the semi-visible bulge in her throat.
There was a brief moment of respite. The two of them just enjoyed the positions they were in. Diluc savored the tight warmth, while Heloise committed the feeling of him in her throat to memory.
"Hel… I'm going to start moving now." He waited for her approval before doing so, but even her nodding was fairly pleasurable.
Both of Diluc's hands came to rest on her head. While he did begin to rock his hips forward into Heloise's mouth, more effort went into moving her back and forth. He was careful not to be too rough with her, but messy wet sounds that edged closer and closer to gagging were easy to enjoy.
Drool bubbled at the corners of her mouth before it ran down Heloise's chin. Some of it might have mixed with the pre leaking from Diluc's dick, but most of that was being fucked down her throat.
Normally more of a warning was given, but the only heads up Heloise had was a loud moan from her brother. He stopped thrusting his hips into her, and instead tugged on her hair as he came down her throat. Heloise whimpered. A few tears budded in her eyes, but only out of pleasure. The cum in her mouth was so hot and thick, and she knew it'd be a waste not to swallow it.
As Diluc pulled out of her, a bit of his cum was coughed up or ran over her lips. He couldn't be upset with her, of course. Especially since she looked so cute, not in spite of but because of the mess.
"Haahh… Did you like your surprise?" she looked up at him with a smile too innocent considering there was still some of his cum on her lips.
"It was perfect." Diluc leaned down, moving his arms to wrap them around her back and pull her up into his arms. His thumb went to her lips, starting to wipe some of the cum away. While he enjoyed the view, his sister was even cuter whenever he managed to fluster her.
He turned her around and laid her back on the bed. Diluc pulled Heloise's legs over the edge and parted them.
"Even though it's my day off, will you let me return the favor?"
It didn't take long for Heloise to realize exactly what he meant. She nodded, maybe too eagerly. Wasn't she supposed to be treating him? Oh, but he was offering…
"Of course you can..!"
And that was all Diluc needed to hear before positioning himself between her legs.
Today had been perfect for a break, it seemed.