Jokes Gone Wrong

(An Encounter with Snape) "Lust potion. One meant to spread from the drinker to others through scent and fluid exchange. You infected me when you kissed me." Potter almost cringed at his words, and her response seemed almost automatic, "I'm sorry," before she paused and then raised her eyes to his again. "How long… how long does it last?" [Other characters' experiences included.]