There will be mentions about some things from episode 1 and 6 like when Alois said that Sebastian smelled good.

"Claude, Alois what good to see you" Sebastian said with a fake smile. "Sebastian, you still smell good" Alois smiled and Sebastian wanted to backhand him but he didn't he just kept smiling. "Well thank you, follow me to the ball room" they both nodded and followed Sebastian to a ball room with many guests. "Where's Ciel?" Alois asked. "There" Sebastian pointed and then disappeared.
One hour later Sebastian walked to the kitchen when he suddenly was pulled into a dark room and someone covered his eyes. "Let me go" Sebastian said and before he knew what was happening that person pinned him against the wall and kissed him. Sebastian sat there shocked. Once the lips left his and the hand disappeared Sebastian heard the door open but was too shocked to look. After a few minutes he heard his master calling him. He quickly stood up and walked back into the kitchen to get the cakes and walked towards the ball room. He gave everyone some dessert but Ciel, Mey-Rin, Finny and Baldroy, even Claude saw that he was slightly distracted. "Sebastian what's wrong?" Ciel asked. "Nothing my lord" Sebastian smiled. Ciel was about to say something when suddenly Claude appeared in front of them. "Hello could I please talk to Sebastian?" he asked. Ciel glanced at Sebastian for a moment before nodding. "Okay, Sebastian you can go talk to Claude but do not fight unless you're life is in danger, That's an order" Sebastian nodded and followed Claude outside.
"What do you want Faustus?"
"Nothing, I just want to chat. You seem rather distracted" Claude smirked knowing what Sebastian was thinking about. Because we all know it was him. He was rather happy about it. He finally managed to get Sebastian's first kiss without him fighting back. "That's nothing of your business" Sebastian said already annoyed. Suddenly someone caught his wrist and pushed him against a tree. Sebastian glared at Claude "Let me go" he groaned. "I don't think so" Claude smirked. Sebastian sighed "What do you want. If it is my master's soul I'm afraid I can't give it to you" "But I don't want his soul"
"Wait what?"
"Like I said I don't want his soul"
Sebastian looked confused. That butler was always after Ciel's soul but why isn't he after him this time. Sebastian pushed against Claude's chest feeling rather uncomfortable. "What do you mean you don't want his soul? You're always after his soul"
"I never actually was after his soul" Sebastian pushed Claude of him. "What do you mean you never were after him?" "I mean that I never wanted his soul"
"Then why were you after him?"
"To get closer to you"
"What?"
"You heard me" Claude smirked. Sebastian stood there surprised and didn't see Claude disappear. "Why would you want to get closer to me-" Sebastian started but then saw that Claude wasn't there anymore. "Claude?" Sebastian asked unsure. Suddenly arms wrapped around him. Claude was hugging him from behind. "You know you sound so cute when you say my name like that" Claude purred in his ear. Sebastian blushed a little. No one ever gave him a compliment. "Let me go Faustus" Sebastian said nervously. "I prefer that you use my first name" Claude smirked. "I'm serious Faustus, let me go" Sebastian felt more uncomfortable and nervous. "Are you uncomfortable?" Claude smirked and turned Sebastian around in his arms. They were now facing eachother but Claude was still hugging him. "Let go" Sebastian said trying to get out of Claude's embrace. Claude just smirked.
He leaned in and Sebastian looked away. Big mistake, he gave Claude access to his neck. Claude smirked and started kissing Sebastian's neck. Sebastian shivered. "S-stop" he whimpered not understanding what was happening. Claude just smirked against Sebastian's neck and loosened his tie to get better access to his neck. "Stop it Faustus" Sebastian said. "I thought I told you to use my first name" Claude smirked still kissing Sebastian's neck. "Fine" Sebastian grumbled. "Please stop it… Claude." Claude smirked. He stopped kissing Sebastian's neck and looked in his eyes. They were full of confusing, fear and anger. "You know my master is right" Claude smirked when the confusing grow. "What do you mean?" "You do smell rather nicely" Claude smirked again when Sebastian's eyes widened. "What's the meaning of this Claude? Did your master order you to try and seduce me." Sebastian asked angrily. Claude's eyes narrowed and he walked forward making Sebastian stumbled backwards in his hold. His head hit the tree and Sebastian groaned thanks to the impact. "I'm doing this because I want to" Claude said: "You know how hard it is to resist how handsome you are?" Sebastian stared at him. One of Claude's arms released him while the other tightened around him. He grabbed Sebastian's chin preventing him from turning away.
Sebastian's eyes widened when Claude leaned in. Claude's lips brushed against his. "You know you're cute when you look like that" Claude whispered. Claude smiled before pushing his lips against Sebastian's. Sebastian realized something at that moment. Claude was the one who had kissed him in that dark room. Claude pulled Sebastian closer to him. He loved every second of the kiss. For him the moment stopped too soon. "Sebastian, come here that's an order!" Ciel yelled. "Claude!" Alois yelled too. Claude pulled away to see Sebastian's flushed face. Even though he hadn't kissed back the kiss was the best one Claude ever had. "To be continued" he smirked and released Sebastian.
They both walked towards their masters, Claude could feel Sebastian's unease. "Sebastian! Where were you, you two have been gone for an half hour" Ciel yelled when Sebastian walked towards him. This time it was Claude's time to get nervous. If Sebastian told them his master would either be furious or Ciel will be furious not that that was bad but if that was so he would never be allowed to go near the manor or Sebastian and that's something he never wants to happen. Sebastian looked at his feet. "This is it, he's going to tell him everything" Claude thought. "I'm sorry master but Claude was talking about stealing your soul and I started a fight with him" Sebastian lied, to say the truth he liked Claude's kiss even though he wouldn't admit it especially not to the other demon, he loved Claude. Ciel backhanded Sebastian. Claude wanted to rip that boy's head from his body for hurting the man he loved. "I told you not to fight" Ciel yelled. "I'm sorry master" Sebastian said. "Come, make me ready for bed and I hope you'll never ignore an order again understood?" Ciel said pissed off and walked inside. "Of course my Lord, I'm sorry" Sebastian said. "Claude let's go" Alois said and they started walking away. Claude took a glance over his shoulder to see if Sebastian was alright. Sebastian stood up and felt eyes on him he looked at Claude and saw worry in his eyes. Sebastian smiled before going inside. "Sebastian lied to his master for me. Maybe he does like me" Claude thought with a smile.