You were in posion class and you weren't really paying attention, you were lost in your thoughts until Snape asks you to smell the posion.

"I can't, Draco's perfume stinks and he won't let me smell it."

Draco looked at you with contempt and did not remain silent, standing up quickly.

"It's your perfume that stinks everywhere

He said angrily until Professor Snape tells them that it is "amortenia." They both looked at each other in amazement while some students laughed.