Oblivious (гет)

Alarmed at the population changes the war wrought, the Wizengamot has enacted a "marriage law": every witch between twenty and forty must get pregnant or prove she's at least making regular attempts. (More like a sex law, really - luckily someone realized marriage isn't strictly required for making babies.) Hermione Granger has finished her arithmancy mastery and has no intention of settling down or having children yet. Especially with Ron, who doesn't understand why she'd need a career. Or see the problem with government-mandated copulation.
Thus, a bargain with the devil: she approaches her former potions professor for help. Severus Snape is intelligent, practical, and adept with memory magic, which makes him a perfect candidate for "making attempts." If he'd agree to regular sessions of sex and then obliviating her afterward, she could follow the letter of the stupid law and give the baby up for adoption without having to go through the messy unpleasantness of sex and derailing her life.
If only life were that simple.