1. Missing or misplaced panties of the stepdaughter. 2. Stepfather staring at stepdaughter's breasts and/or buttocks. 3. The stepfather using long embraces (sometimes accompanied with an erection) as greetings and farewells, as an excuse to squish the stepdaughter's breasts into his body. 4. Expensive presents for the stepdaughter. 5. Jealous behaviour towards stepdaughter's boyfriends.
stepfather: (barrels over and hugs stepdaughter) Good morning pumpkin.
stepdaughter: (Tries to squirm out of the perverts long hug.) What's wrong with you? Let go of me.
stepfather: I've been diagnosed with stepfather syndrome.