Antonio was Adrian's best friend and first boyfriend. They were next door neighbors and knew each other since elementary school. They rode the school bus together, hung out, and had sleepovers. In the episode Be My, Be My Baby, Adrian talks about him when she and Ricky go to therapy together. Dr. Fields asks her about her first sexual experience, which was with Antonio. Adrian says that they brought their sleeping bags up to the roof of their building and zipped theirs up together. Adrian says that it was a wonderful night, that they listened to music, and watched the moon. They decided to have sex because he was going away do cancer treatment. They always wanted to be each other's first and last. They talked about getting married and having children together. Adrian tells Ricky that he's the first guy she's had feelings for since Antonio.
Antonio's only been mentioned in Be My, Be My Baby, he's never been seen on screen.