Ciel was fuming. He was sitting at the far corner of the pub, nursing one of the most disgusting ales that he had ever tasted, and watching his butler flirt with a prostitute.

They were on a case to investigate a recent series of murders where men of various ages were found dead with their hearts cut out. At first, Ciel only read about it on the newspaper, until one day, a nobleman was found in a similar fashion and suddenly, the Queen wanted her Watchdog on the case.

Their investigation led to the discovery that these men had been engaging the service of a local prostitute. So now they had to find which one of them was the culprit. However, Ciel knew that they wouldn't talk to just anyone. So he devised a plan. They, or rather, Sebastian would have to extract information from the local prostitutes. If they were lucky, they would get it on the first try, if not, hopefully they'd get a lead.

Ciel wasn't bothered by it. After all, this wasn't the first time that they had to take this approach. So, Ciel thought nothing of it. It was just some harmless flirting, right?

Wrong.

When the woman ran her hand along Sebastian's arm flirtatiously, Ciel wanted to yank her off his butler and tell her off for daring to touch what belonged to him.

Ciel's grip on the mug handle tightened when he saw that the woman was practically draping herself all over his mate, giggling and batting her lashes at him. He unconsciously let out a low growl.

Sebastian, being Sebastian, smiled genially as he tried to find out the name of the prostitute that they were looking for. He was fully aware of the glare that his master was directing at him and his... companion. He inconspicuously extracted himself from her grasp and put some distance between them. While he did enjoy (secretly, of course) his mate's possessive behaviour, he wasn't going to upset him unnecessarily. They were better than that. Their relationship was better than that.

Ciel was just about to lose it when Sebastian finally got to his feet, said something to the woman, and then he walked to the exit. Ciel waited for a minute or two before getting up. He stepped out of the door and started walking. He didn't care where he was going, his butler would fall into steps behind him either way.

"Well?" Ciel prompted when he felt Sebastian's presence behind him.

"I did not get her actual name, but she is known as 'Miss Valentina'." Sebastian reported. "Apparently, nobody knows her actual name, not even her... colleagues."

"Did you at least get a description?"

"Nothing useful, sir." Sebastian said.

Ciel honestly didn't know what prompted him to say his next words, but before he could stop himself, he snapped, "So much for all those flirtings that you did. Perhaps you should just bed her. Then maybe you'd get something useful."

Sebastian was so surprised, he actually stopped walking. "My lord?"

Ciel was angry at the woman for flirting with his mate, at Sebastian for flirting back, and at himself for being angry in the first place. It was all so confusing to him. He kept on walking, not caring if his butler was following him or not.

When they reached the main road, Sebastian hailed them a cab, but they didn't say anything to each other and the carriage ride was probably the most awkward and uncomfortable ride that Ciel had ever taken with his butler.

They reached the townhouse and still, no word was spoken as they climbed up the stairs that led to the main floor.

"I shall prepare your bath, Young Master." Sebastian finally said, breaking the silence.

Ciel grunted, but still said nothing. He had acknowledged to himself that he was jealous. Logically, he knew he shouldn't be. Hell, he was the one who had ordered Sebastian to approach the prostitute. But he couldn't help it. And throughout the carriage ride, Ciel had been thinking about all of those times that his demon had flirted with others, even before they got together. He didn't even know why he thought of those things. It was like he couldn't think straight and his thoughts were all jumbled together.

Ciel had always been proud of his intellect. He knew who he was and what he could do. He was smart, he was a master at games, he was a chess prodigy, but all of his logic went out of the window and was replaced by some... primal instinct the moment someone went as far as touch his mate. It was, to be honest, embarrassing. He knew he was better than this, he knew they were better than this, but he had never been jealous before, so this feeling was entirely new to him and he found himself at loss. And whenever Ciel wasn't sure of his feelings, he reverted to anger. It was a habit that he could never quite break.

"Your bath is ready, my lord."

Ciel snapped out of his musing to find his butler standing nearby, waiting.

"I'll bathe myself today." Ciel said.

Sebastian looked like he wanted to protest, but after only a second, he bowed slightly. "As you wish."

Ciel walked to the bathroom and undressed himself. While he still couldn't dress himself, undressing was a different matter. After all, he had had a lot of practice on a certain butler uniform. Once he was naked, Ciel stepped into the tub and sank into the hot water. As always, it was at the perfect temperature.

Soon, it occurred to Ciel that he didn't know where the soap was. He looked around, trying to locate it, but couldn't spot it. He got up from the tub and shivered slightly as the cool air hit his body. He stepped out of the tub, dripping water everywhere, to hunt down the soap. Once he had found it, he quickly stepped back into the tub, eager to escape the cool air and get back into the hot water.

Ciel started washing his hair. His mind shifted to tonight's events again and he sighed. He was jealous and he was being completely unreasonable, and now, he was sulking. He was seventeen years old, and yet, here he was, behaving like a three years old throwing a tantrum over some... some whore.

Suddenly, Ciel felt ashamed. For years, Sebastian had been forced to endure watching him and Elizabeth and he had been gracious about it. Sure, he was possessive and jealous, but he could control himself. And now, when the situation was reversed, Ciel couldn't control himself. The situation, as it were, wasn't even reversed. That woman was nobody and she didn't even do anything. Ciel also had to acknowledge that Sebastian had tried to put some distance between himself and her at the pub. He was still following his order, while at the same time making sure that he respected Ciel and their relationship. And still, Ciel threw a tantrum and took it out on his butler.

Ciel's thoughts were interrupted rudely when some of the suds got into his left eye and he yelped at the sudden sharp sting. He dropped the soap into the water and scooped up some water to rinse his eye, completely forgetting that he was just holding the soap in that hand. He cursed and scrunched his eyes shut as it stung badly. He got up hastily and scrambled out of the tub. The floor was wet and slippery and he involuntarily let out a loud shriek when his foot slipped and he fell backwards. He was promptly caught by a pair of strong arms.

"Young Master, what happened?"

"My eye!" Ciel yelled urgently. It felt like his eye was burning. "Soap!"

Quickly, Sebastian picked up the earl and brought him to the sink. He put Ciel on his feet and encouraged him to rinse his eye.

"Please remove your hand and rinse your eye, sir." Sebastian instructed.

Ciel did exactly that. He rinsed his eye over and over again with the cool water until the stinging and burning sensation subsided, but still, he kept on rinsing until the burning sensation was gone, leaving behind an uncomfortable feeling. He vaguely noticed that he was wrapped in a big and fluffy towel by then.

"That is the worst." Ciel said when he finally stopped rinsing.

"Please let me see..." Sebastian murmured as he examined the eye. It was red, but it looked okay. He soaked a soft towel under the cold water and gently dabbed at it and Ciel sighed at the cooling sensation. "Will you allow me to bathe you now, my lord?"

Ciel nodded and sneezed. He was still covered in suds and his hair had some bubbles on it. He clearly needed a proper bath.

The water had cooled, so Sebastian poured more hot water into the tub. He worked quickly and once he was done, he dried Ciel off and put him in his pajamas as the teen had been sneezing.

"Please get some rest. It has been a long day." Sebastian said, tucking him in. He was worried that Ciel would get sick. That would be the last thing that they needed since they were in the middle of a case right now.

Ciel grabbed Sebastian's hand. "I'm sorry." He said. "I was behaving so childishly."

"Oh?" Sebastian raised his eyebrows. "And what does the young master mean by that?"

"You know what I mean." Ciel grumbled.

"Please forgive me, my lord, but I am not a mind reader."

Ciel narrowed his eyes. "Bastard! You're going to make me say it, aren't you?"

"Whatever do you mean, sir?" Sebastian asked, but there was a twinkle in his eyes.

Ciel contemplated telling him to just forget it, but in the end, he decided that he had to own up to it. "I was... I got jealous when she put her hands all over you and I got angry and took it out on you."

"If I recall correctly, she did not put her hands all over me." Sebastian said.

"She draped herself all over you like some whore!" Ciel said incredulously.

"Pardon my candour, but that is what she does for a living." Sebastian pointed out.

Ciel gaped at him and then let out a frustrated snarl. "Fine! Why did I even bother?!"

"For the record, I was not going to let her put her hands on me." Sebastian said. "It was your order..."

"I'm aware!" Ciel snapped.

"It was your order, thus, I had to obey." Sebastian continued calmly. "But I did not enjoy it at all. In fact, I found it to be uncomfortable."

"You're lying."

"I do not lie to you, my lord. You seem to forget that at times." Sebastian said.

"You seemed to enjoy the attention." Ciel said sulkily.

"I can assure you, I did not." Sebastian said.

"Why not? She looked pretty enough."

"Because she is not you." Sebastian said simply. "You need not be jealous, my lord. You have nothing to be jealous about. I am yours, completely and irrevocably yours. So, how can I enjoy other people's touches when I already belong to you? When your touch is all I want and need?"

Ciel blushed.

"Besides," The teasing smirk was back on the demon's face now. "You were glaring at us like you wanted to kill her, how could I enjoy myself? Although, I must admit, I did enjoy this possessive side of yours."

Ciel glared at him. "Well, I don't like it when people touch what's mine!"

Sebastian chuckled. "Your possessiveness could rival that of a demon."

"I learned from the best." Ciel said and yawned. "I'm going to sleep. Take a long bath before coming to bed. You smell like perfume."

"Yes, my lord." Sebastian said and tucked him in before straightening up. He took a bath, cleaned up, and changed into his pajamas before slipping into bed. As if sensing him, Ciel stirred and reached for his demon. Sebastian wrapped his arms around his mate and held him close as he slept.

"Young Master, I'm afraid we might have a problem." Sebastian said two nights later.

"What is it?" Ciel asked.

"Our Miss Valentina is not what she appears to be." Sebastian said.

Ciel looked confused for a moment before realization dawned on him. "You mean, she's not... human?"

"Yes, it appears so." Sebastian confirmed.

"What is she then? A demon? A reaper?"

"Neither. She is a succubus." Sebastian told him.

"A succubus? What is that?" Ciel asked.

"A succubus is a creature that appears as a woman and their primary goal is to seduce men. There are several different types, but this one apparently enjoys ripping out people's hearts." Sebastian explained.

"How do we kill her?" Ciel asked.

"The same way she kills her victims, by ripping out her heart." Sebastian said.

"That should be easy enough for you, right?" Ciel said.

"Not quite." Sebastian said. "In order to kill her, I will have to rip out her heart when she is in her true form. And her true form will only show when she is ready to have sex."

Ciel hesitated. "You'd have to seduce her then?" He wasn't sure if he'd be able to handle that. He could barely control himself when someone was flirting with Sebastian.

"No. She will sense that I am a demon and she might flee." Sebastian said. "She knows that we demons are not interested in that kind of... liaison with her kind."

Ciel looked thoughtful. "Then how are we going to get her to show her true form? We cannot take any risk that she would kill another... Oh." His eye widened in realization.

No response.

"And are you going to be okay with that?" Ciel asked.

"At least I will have the satisfaction of ripping her heart out." Sebastian said.

"No." Ciel decided. "We'll find another way. Besides, I don't fancy being groped by some inhuman whore."

As it turned out, they didn't have any choice for there was another murder that night.

The next night, Ciel was bathed thoroughly and was dressed in plainclothes.

"I will be near, but not close enough that she can smell me." Sebastian said quietly.

Ciel didn't like this at all. "Sebastian..."

"I will protect you. Please do not worry." Sebastian said.

"I know that. I'm not worried about me." Ciel said and reached for the demon's hand. "Look at me." He said and waited until his butler looked at him. He could see the anger already brewing in those garnet eyes. He stroked the demon's cheek to soothe him. "I'm yours, just as much as you're mine. You belong to me and I to you. Nothing and nobody can change that."

Sebastian swallowed his anger. This was not the time for that yet. "Yes, of course."

Ciel smiled. "Good. Let's get this over with then."

Sebastian bowed. "Yes, my lord."

Ciel approached the woman. She had long blonde hair, a pair of blue eyes, and full red lips. Overall, she was what people would call a beautiful woman. He supposed, she had to be. Since it was literally her nature to seduce others.

"Miss Valentina?" Ciel asked timidly.

"Yes. Oh, aren't you sweet?" The woman looked at him.

"Can we go somewhere... private?" Ciel fidgeted slightly. He took out some coins from his pocket and offered them to her, his intention clear.

A few seconds lapsed as the woman seemed to study him. Ciel hoped that she wouldn't smell his demon on him. Else, this would be for naught.

"Follow me." 'Miss Valentina' said and led him away.

They headed to an abandoned alley and Ciel couldn't stop himself from wrinkling his nose in disgust. It smelled so awful. He'd need several baths to get rid of the smell.

"So, what do you want, boy?" The woman asked coyly. "Let's see... These would buy you some good time."

"I... I'm not sure..." Ciel stammered.

"Oh? Shy, aren't you? That's okay." The woman pushed Ciel against the wall. "Let me take care of you." She purred. Then she started to undo Ciel's shirt button, her finger trailing down the newly exposed skin.

Ciel fought his instinct to flee and he could feel his skin crawling. He could smell her breath and it was sickeningly sweet. He involuntarily turned his head away.

"Hey, eyes on me, sweetie..." 'Miss Valentina' said.

"Right, sorry. I'm just... nervous." Ciel said. "Can, uh, can we get on with it already?"

"So impatient..." The woman said. "But if you're so eager..."

Then woman started changing. Her hair turned brown, her blue eyes turned into a shade of murky yellow, and her skin paled and glowed. Instead of wearing her street garb, her clothes melted and changed into skin-tight black layer that left nothing to the imagination and her fingers elongated and shifted into claws. She was both stunning and frightening at the same time.

"You don't seem to be surprised." The succubus observed.

Ciel looked at her steadily. "I'm not."

The succubus narrowed her eyes. "You're one interesting human... Why are you here?"

"I'm here to investigate the recent murders." Ciel said.

The succubus laughed then. "Oh, is that so? And now that you've found me, what are you going to do, hm? Are you going to arrest me?" She ran her claw along Ciel's cheek. "I think not, my dear boy. You're going to end up like them."

"I'm not here to arrest you." Ciel said and pushed her claw away. "I'm here to make sure that you go away for good." He pulled off his eye patch, revealing his Faustian mark.

The succubus' eyes widened in shock. "You're marked!"

"I am marked." Ciel confirmed. "And he is not happy that you've touched something that belongs to him." He looked pointedly past the succubus' shoulder.

The succubus turned around and came face to face with an angry Sebastian.

Sebastian's eyes flashed dangerously and his lips were drawn back in a furious snarl. He looked positively lethal. The only thing stopping him from ripping out the succubus' heart was that his master hadn't given him any order yet.

"A demon..." The succubus hissed.

"Your order, Young Master?" Sebastian asked for his order.

"Sebastian, this is an order! Kill the succubus!" Ciel commanded.

"Yes, my lord." Sebastian growled his compliance before leaping forward.

Ciel moved to stay out of harm's way. He fumbled with his shirt and redid the buttons. The smell of the alley and the feel of that creature's hand on him disgusted him. He would love nothing more than a bath, preferably with his demon. But that would have to wait. The said demon was busy right now.

Ciel watched as the fight unfolded. It wasn't going to be a long fight, he could tell. The succubus was no match for Sebastian. She was driven by her survival instinct, but that wasn't enough to protect her against the furious demon.

Soon, the fight came to an end and Sebastian pierced the succubus' chest with his claws and ripped out her heart, drawing one final scream from her before he squeezed the appendage in his hand, destroying it completely. With that, the succubus' body turned into ashes.

Sebastian stood there as the object in his hand turned into dust. His eyes were still glowing and his hands were still adorned with claws.

Ciel approached him and reached to take his mate's hand in his.

Sebastian was startled at the touch and he turned to look at his master.

"It's over, Sebastian. Come, let's go home..." Ciel said softly. He felt the claws in his hand retreated and he was holding the butler's human hand, sans gloves.

"Yes, my lord." Sebastian nodded. He took out another pair of gloves from his pocket and put them on. "Are you alright?"

"Yes, I'm fine. But I really want to take a bath." Ciel said and his lips quirked into a smile. "Preferably with you."

But the demon didn't return his smile.

Ciel's smile disappeared quickly. "What's wrong?"

"She touched you and I can smell her all over you."

"Which is exactly why I need a bath." Ciel said.

Sebastian composed himself. "Yes, of course, sir. Please forgive me. Let us go home."

They left the dingy alley and Sebastian hailed a cab to take them home.

Sebastian was silent during the ride back to the townhouse, but Ciel could feel his tension. He knew that whatever it was, it would have to wait until they reached the privacy of the townhouse.

Once they had reached the townhouse and the door closed behind them, Ciel turned around to face the taller man.

"Out with it then, what is bothering you?" Ciel asked without preamble.

"You were right, Young Master. You need a bath. Now." Sebastian said, impatience lacing his voice. It was quite odd coming from him.

Ciel didn't complain though. They went upstairs and Ciel was about to sit on the bed to wait for Sebastian to prepare the bath, but the butler stopped him.

"No, please do not sit there." Sebastian said and guided Ciel to sit on the chair instead.

"Why not?" Ciel was confused. He looked at his trousers, thinking that maybe it was too dirty, but it looked okay.

"You smell of her and I would rather not get her smell on our bed." Sebastian said. "I will prepare your bath now, my lord." He bowed slightly and left.

Ciel sniffed his own shirt and it smelled like garbage, but there was a hint of something sweet. He chuckled. Just a few days ago, he told the demon to take a bath first before getting into bed after their encounter with that prostitute, and now, the situation was reversed.

Once the bath was ready, Ciel was stripped and he stepped into the tub.

"Join me?" Ciel asked hopefully.

"No, sir. I would rather make sure that you are very clean." Sebastian said and started washing Ciel.

Was it his feeling or was Sebastian scrubbing him more roughly than usual?

After his bath, Ciel was dried and that was when things started to get... strange.

Sebastian leaned down to kiss Ciel, wrapping his arms around his waist. He slowly trailed kisses to the earl's jaw and neck, nipping at a particularly sensitive spot.

Ciel moaned and titled his head back to give the demon a better access.

"Mine." Sebastian growled, his arms tightening around the young man.

"Mm... Yours..." Ciel agreed. "You're wearing too many clothes though..."

Usually, that would be Sebastian's cue to start taking off his clothes, but not tonight. Instead, he returned to Ciel's lips, kissing him deeply.

Ciel eagerly returned the kiss. His hands were busy working on getting his demon naked as soon as possible. Once he had taken off the tie and waistcoat, he started working on the shirt. He managed to get the first few buttons undone before Sebastian picked up Ciel into his arms and carried him to bed.

"Do not dress me!"

"Oh, I have no intention to." Sebastian growled.

Before Ciel could say anything else, Sebastian had climbed into bed with him. He covered Ciel's body with his own and started kissing him again. His hand moved to capture Ciel's wrists and pressed them on the mattress, above the earl's head and he used his free hand to hold himself up. He placed open mouthed kisses along Ciel's jaw, down to his neck. Ciel could feel the demon's fangs grazing his skin and heard him mumbling, "Mine".

Ciel moaned and closed his eyes, enjoying the sensation, until the hand around his wrists tightened almost painfully. That was when he realized something was wrong.

"Sebastian?" Ciel called.

The only reply that he got was the tightening around his wrists.

"Sebastian, what's going on?" Ciel asked.

No reply.

Ciel started struggling, but it was futile.

"Sebastian, get away from me! That is an order!" Ciel finally said.

And just like that, everything stopped and Sebastian practically jumped off the bed, but he was looking at Ciel wildly, lustfully, and possessively. His eyes were glowing and his fangs were bared. He looked predatory. His body was tense, as if he was ready to pounce, with only Ciel's order holding him back.

"Snap out of it, demon!" Ciel yelled, his voice sharp and commanding.

Sebastian shook his head to clear his mind and he slowly relaxed his stance. Then he lowered himself to his knee and bowed.

"Please forgive me, my lord. I was out of line."

Ciel shook his head and rubbed his sore wrists. "It's fine. Just tell me what the hell is going on with you."

"It seems that the encounter with the succubus has some... side effects."

"Like what?" Ciel asked. "And get up."

Sebastian got back to his feet. "At the core, a succubus is a sexual being and they reeked of pheromones. Thus, when she touched you, she left her pheromones all over you and it triggered something more primal in me, something that makes me want to claim you, to erase her traces from you. Just like how you do not like it when people touch what is yours, I too, do not like it when people touch what is mine."

Ciel frowned. "But you've never acted like this before. Not even when Elizabeth hugged me."

"Lady Elizabeth is not a succubus." Sebastian pointed out.

"Good point. So, that's why you were scrubbing me so hard? To get rid of her pheromones?" Ciel asked.

"Did I hurt you?" Sebastian asked. Now he sounded worried.

"No, it's fine. Now that I know about it, I want to make sure that it's gone completely too." Ciel said.

"Of course, my lord." Sebastian went to retrieve Ciel's pajamas.

"What are you doing?" Ciel asked. "I thought you said that you have no intention to dress me?"

"That was before..." Sebastian said unsurely.

"Before what?" Ciel raised to his knees, a cheeky grin on his face. "I thought you wanted to claim me, demon? Or have you taken to lying to your master now?"

"Please do not tempt me, my lord. I do not wish to hurt you, nor scare you."

"You were being a little too rough. I don't mind, but give me a warning next time. And you definitely don't scare me." Ciel said.

"It is not a good idea to tempt a demon." Sebastian said.

"Maybe not, but you're not just any demon. You're my demon." Ciel said. "I know that you will never hurt me. Not because you can't, but because you don't want to."

Sebastian was stunned at his words. Once again, his master had managed to surprise him. He was being so confident, so arrogant in his claim. But when their eyes met, he saw no arrogance in those eyes. Instead, he saw trust. Ciel trusted Sebastian not to hurt him, he trusted Sebastian to protect him, to love him.

Sebastian would never forgive himself if he ever broke that trust, if he ever let his master, his mate, get hurt by his own hands. "I will never hurt you."

Ciel smiled. "I know." He stretched out his hand. "Come to bed, Sebastian."

And really, there was only one answer to that. "Yes, my lord."