Super Mario syndrome
When a guy feels strong romantic and intimate feelings to a girl that barely acknowledges his existence, and chases after her, much like Mario does in many of his video games for Princess Peach.
Person #1: Did you see how hard Jack's trying to get Stacy to fall for him?
Person #2: Sounds like he has severe Super Mario syndrome to me.
Person #2: Sounds like he has severe Super Mario syndrome to me.