Work crush while in a relationship?

I started a job at a new location about a year ago and a guy who works there started showed interest in me. He started flirting by text and I told him I have a boyfriend who I live with and he respectfully stopped. Now we’ve been just having normal coworker/friend conversations in person and I’m starting to get really attracted and attached to him even though I definitely know I could not see myself in a relationship with him. I find myself thinking about him for hours after work but when I’m away from him for a while I’m fine. How do I get over this work crush? Will the feelings just fade over time?