Claimed (SebastianXCiel)

This fic is for a friend of mine from Tumblr who makes quite the Sebaciel prompts... I wanted to honor her amazingly wonderful idea, and turn it into an actual one-shot... a Smutty one-shot.
I hope you appreciate my 8,000+ worded fic, and here's the prompt:

"Sebastian is a professor at some University, and Ciel is his student - but when they're both home, they're lovers. They decide to keep it a secret because Sebastian is afraid that people would start thinking that Ciel's perfect grades are because he's dating a professor, when honestly, it's all because of his own hard work. Bu hiding their relationship would be hard, especially if the older one is constantly being a horny bastard who can't control his libido; and the marks that are on Ciel's neck scream 'NOTICE ME' to everyone around him"