WALLINGFORD — A town woman faces charges after police say she discovered her teenage son having sex inside her home early Sunday and stabbed him in the arm. Dina Tapler, 47, of 12 Sycamore Way, was charged with second-degree assault, first-degree reckless endangerment, risk of injury to a minor and second-degree breach of peace. Police responded to the home after receiving a call about the injured teen at about 3 a.m., said Lt. Cheryl Bradley. The teen had a friend staying over, and at some point during the night other teens came to the home. Tapler heard noises coming from the bedroom and found the teens engaging in sexual acts, Bradley said. She kicked the friends out and held a kitchen knife to her son’s neck, police said. The two struggled and Tapler stabbed the teen in the arm, Bradley said. The teen was taken to a hospital for treatment and released to a relative. Tapler was taken into custody and released on $5,000 bond.