Carla Marie Rizzi was a photographer's assistant who met Steve when her boss, Dustin Brady, shot photos of the basement at the house on Woodlawn Avenue.
She flirted with Steve, and after numerous ups and downs, they made love on March 25, 1984 (Cf. Chapter 21 - The Times They Are a-Changin' in AWLL 1 Book 9 - Anala.) She told Steve to leave immediately after sex, and they never dated again.
Fast forward to Chapter 72 - Out of the Blue in AWLL 2 Book 2 - Stephie, where Steve is served with a paternity lawsuit.