p-dogging
A guy thinks he's the main man and starts tailing some girl like a lovesick mutt, only to find out he's just in the way of someone else getting laid.
My cousin p-dogged my sister for a week. Still didn't get any.
He followed her to the store. She bought a sandwich and he bought a sandwich. Both had no idea why.
He was so obsessed he texted her every hour. She blocked him. He still didn't get it.