WWDD: S1E7 “ANGEL”
Dawn is doing homework at the gallery while her mom works late. When they get home, Dawn darts out of the car ahead of Joyce and upstairs before Buffy intercepts Joyce at the door. Dawn is disinterested in their conversation until she hears the sound of a man’s voice. Buffy had a boy over?! Alone?!! Dawn listens, out of sight, at the top of the stairs as Buffy says an obviously fake goodbye (c’mon mom!) to her BOYFRIEND! She waits until she hears Buffy’s door closing and quietly stations herself outside. Did he just say that his family was killed by vampires?
The next morning, Dawn repeatedly gives Buffy the “I know your secret!” look while Buffy feigns ignorance. That night, during dinner, Dawn pieces together that this mysterious man is in Buffy’s room again by watching Buffy race through dinner and back up to her room with a plastic bag of leftovers. (Seriously, get it together, Mom!). Dawn is eager to catch Buffy red-handed, so she quickly tells Joyce she’s done, darts upstairs, and barges into Buffy’s room just in time to see BUFFY KISSING A BOY! The sight of Dawn bursting through the door causes Angel to abruptly turn away from the kiss and when he turns back, this yellow-eyed, fanged man looks nothing like anything Dawn has ever seen before. Dawn runs back to her room afraid. Buffy later comes into Dawn’s room and tries to comfort her and reassures her that what she saw on the man’s face was just a trick of the light.
The next day, Buffy is relieved to learn that Dawn, who's been asking questions, gets invited to a sleepover at Janice’s house. During the sleepover, Janice’s mom gets a call from the hospital and Dawn learns that her mom fainted and fell onto a BBQ fork. Dawn thinks this is weird because they don’t have a BBQ fork. When Dawn later sees Joyce’s wounds on her neck, she begins to doubt that what she saw on Buffy’s boyfriend’s face was just a shadow, and has a sinking feeling that maybe vampires are real.