Black Butler II/Ho Yay

Kuroshitsuji II had such amounts of Fan Service that a significant number of fans actually thought it excessive. It is possible to find Ship Tease between every combination of the four main characters.

Sebastian/Ciel

• The beginning of episode 6 of season 2 has Sebastian making like he's about to kiss Ciel, and he acts possessive over Ciel (or Ciel's soul) declaring to Claude that "Young Master is mine." or "He is my young master." He also tells Claude that the fact that someone other than himself touched Ciel disgusts him as well as saying "The young master belongs to me."
  • Not to mention the line in which Sebastian says to Claude, "That white, sticky spider's thread of yours tarnished bocchan's... soul."
• Sebastian fighting over Ciel with Claude, which leads to both Alois and Grell implying that he's in love with Ciel. Sebastian doesn't deny it, and, in fact, agrees while fighting Claude in episode... 10? That he's not fighting for Ciel's soul...

Alois/Ciel

• In episode 1 of season 2 when Alois sees Ciel he reacts with great excitement and says "Finally I have you, Ciel!"
• In the 5th episode of season 2, Alois cross-dresses and flirts with Ciel via holding his hand, caressing his face, putting his hands behind his head, licking his ear, and outright telling Ciel that he "wants" him.
  • He also tells Ciel that if he's in pain he'll lick him to heal him up.
  • In the 6th episode of season 2, Alois intentionally provokes Ciel by dancing with his fiance Elizabeth and at the end of the episode they lock gazes with Ciel declaring "I will definitely kill you!" and Alois declaring "I will definitely make you mine!"
• Episode 7, season 2: Alois straddling Ciel and getting close to his face.
• As seen in the above picture, there's plenty of Ho Yay regarding these two in official art and of course fanart.
• Alois's final wish results in Ciel's immortality. Aww!

Claude/Ciel

• Episode 6: Claude reminisces the last time he touched Ciel and remarks "The feel of him. One rarely encounters something so fine."
• Episode 9 has Claude declaring (in regards to Ciel) as he's knitting how he wants to "stick my needle into his soft skin and suck out his sensual soul".
• In episode 10, Claude is basically orgasming over Ciel, even going as far as to kiss his foot, while Sebastian is watching outside of the mansion with a some-what jealous face.

Claude/Alois

• Before season 2 had even started, they gave us a lot of hints/fanservice in the scans (e.g. here).
• In episode 1 of season 2, Alois begs Claude not to leave him alone, and Claude holds Alois's face in his hands and declares he'll never leave him alone.
• In episode 8 of season 2, towards the end Alois tells Claude "I have only you. There's only you left in my world!" He then tearfully hugs Claude's leg and says "Don't ever leave my side! You are...you yourself are...My Highness!" It almost sounded like he was giving Claude a love confession. Claude tenderly holds Alois's face in his hands and leans in so close their lips are almost touching right before killing him.
• In episode 11 of season 2, Alois tells Claude "Claude, you ensnared my heart in a spider web, my eternal Highness. I wanted your love".
  • And in episode 12 of season 2, Claude actually acknowledges Alois's wishes and it's hinted he will live on in love in the afterlife with him, Luca, and Hannah.
    • Claude/Alois is pretty much confirmed as of episode 12.
• In the Spider's Intentions OVA Alois doesn't want Claude to ever leave his side.
• As of his Character Development Alois appears to be Yandere for Claude and seems to actively do things to piss off Claude and get his attention.
• Claude's catchphrase can even be interpreted roughly as "I want nothing but to deeply desire my master."
• In a scene from episode 6 Claude gets really close to Alois's face and tells him "I want nothing but to devour you in one hell of a bite" or "I intend to make one hell of a feast out of you."

Other

• When Alois first meets the mysterious stranger later revealed to be Sebastian he leans into him and smells him before saying he "smells good".
• All the subtext between Sebastian and Claude in episode 6.
• Viscount Druitt flirts with cross-dressed Ciel again in the Ciel In Wonderland OVA.
  • And he also wears a look of great sympathy upon hearing Alois's sob-story.
• In episode 6 in response to hearing Sebastian play beautiful sounds with some water glasses, Agni's response is to cry tears of joy, says Sebastian has an "immaculate soul", and then comments "How fabulous! You are a truly fabulous man, Sebastian!"