"Oh, Severus, how wonderful!"
"Not that I mind your affection, but what—"
"I know about the uncles! It's lovely of you to have agreed to help Harry and Draco with their fertility potions, and in the traditional manner, as well!"
"I beg your—"
"There's no need to beg me for anything. Of course I don't mind. Collecting the necessary semen should be done by hand, and it's not cheating if done for ritualistic purposes."
"I'm glad you're going to help them in spite of your phallus aversion. I'm so proud of you!"
"Here? Well, if you insist."
Author's note: Uncles have bigger . . . brains than 'ncles. >:)