Buffy The Vampire Slayer (1997) - 4x18 - Where the Wild Things Are

Buffy and Riley are spending all their time in bed (and they're not sleeping). Their round-the-clock exploration of each other awakens the spirits of children who were sexually repressed by their foster mother back when Lowell House was a home for orphaned and runaway kids. Willow, Giles and Tara divert the angry children while Xander and Anya go to try and stop Buffy and Riley.