Three Wizard Tots and a Potions Master

AU, De-age. During dinner with the Order at 12 Grimmauld Place, a duel breaks out between Snape and Sirius. When the mist clears, Snape finds himself the reluctant guardian of THREE little tots: Harry, Remus AND Sirius. As he tries to protect them from Voldemort and their own dark pasts, will his tiny arch-nemeses worm their way into his cold, dead heart?