Forbidden (Sebastian x Reader x William) {lemon}

Warning: this story contains scenes that are not appropriate.

As Ciel's 17 year old cousin, you were living with him to ensure his safety. Well that was your parents choice even though they knew that he was well-protected, but still, you were needed by him being his beloved cousin... And you started to like it there, for Ciel lets you do anything in his manor.
But when he noticed something, he banned Sebastian from talking to you.
After months being there you met William Spears, a reaper, who you were deeply in love with. But little did you knew that someone already fell for you first...

Well... The description is kind of, lame, and confusing. But you know, just... Read it to know more...