On a random evening, a friend of yours had decided to leave quite a few hickeys on your neck that you had failed to hide well with make up. However, during your potions class, your make-up smeared and Severus -- who was seated next to you saw the exposed hickeys pretty quickly. He didn't seem pretty pleased and followed you out when class was over, gripping your arm tightly with a serious expression on his face

"What's that on your neck?!"