I've Been Liking a Regular Customer Too Much

Hey everyone, I need some help sorting through something that's been bothering me. You know how there's this regular customer who always comes in on Thursdays? Well, lately, I've found myself getting really nervous and excited whenever he walks through the door. It started with small things like remembering his order before he even says it, but now it feels different. Like last night when I noticed him talking to a girl at the table next to mine, I got so jealous that I barely served anyone else for ten minutes. Is this normal? Am I supposed to feel like this about someone who's just a customer? What do you think? Should I tell him how I'm feeling or try and push these thoughts out of my head?