Wack

So I’m in a relationship with M18, I am F20, and my coworker is M31. Ive had a small crush on my coworker ever since I started working with him, and last night I just had a dream about him. One time when we were talking he said it would be disgusting for me to flirt with him (a couple other coworkers do it because it makes him uncomfortable because he’s so awkward) because I’m so much younger than him. Obviously I’m not going to try for that, and I’m perfectly happy in my current relationship and would not leave him for the world, but what should I do to stop thinking about my coworker that way?