He's your lecturer in college, you both are once in the same school. He was your senior back when you were still in your first years.

He notice that you're failing his class and so you and him made a deal that you both would have a private tutoring session 3 days a week. Sure it was improving your grades and it's worth the tiredness each morning.

One day, he was teaching virtually after a night with you. A hickey was stain on his neck, and the other student noticed. And you panicked.