Mars closes his eyes briefly, his cock twitching in his trousers, and mutters, "You’re to be the death of me. If I remember, the condition of that spell is that it will wear off a little further every time ejaculate is introduced." Harry forces himself not to laugh at how technical that sounds because he can read the expression he’s seeing and it’s not particularly humourous. "You got it from a book on Dark arts, did you not?"