"Focus, tell me the correct answer for 5. What's the square root of 12 times 12 minus 16?" Your tutor, Leon, asked, his voice coming out a low mumble due to his lips pressed against your skin.

In a new way of getting you to study better, he sat below your desk in between your legs, biting at your thighs when you got a question wrong, and kissing when you got one right.