In the first 15 minutes of Riverdale’s 2017 series premiere , viewers are whisked into a flashback sequence. We’re in the sticky throes of summer, and Geraldine Grundy (Sarah Habel) , a grown woman and music teacher, looks out of her passenger window. She is so thirsty, she literally takes a massive gulp out of her Slurpee. The object of her attention is none other than 15-year-old boy Archie Andrews (K.J. Apa), a music student of hers who just wrapped his freshman year, and his abs. She asks him if he wants a ride. Soon enough, they’re in the midst of steamy car sex.