Coworker crushing on me??

So one of my coworkers has been real talkative towards me lately. We’ve been bonding pretty well: finding things in common, teaching other different ways to do our jobs, him talking about his girlfriend and me talking about my fiancé, etc. well today was different.

I was kind of mad at my fiancé and told my coworker about us being mad at each other. He told me to just breathe and rethink the situation. I called my fiancé during my lunch break, skipping lunch with the coworker to do so, and apologized for our little argument last night and that I’ll try better in this relationship. My fiancé apologized, too, and we were on good terms. My fiancé surprised me by coming to my job to pick me up and he did the sweetest thing! He bought me a new outfit and said we were gonna have a date night that night to my favorite PHO restaurant, which is open for dine in and he had already reserved a table for us. He presented this little surprise in front of everyone, so when I rushed to get clocked out and to get my stuff from the office, my coworker stopped me right when I was heading out the door. “Your fiancé is a lucky man.” He squeezed my shoulder a bit saying this and then tells me to have fun on our date. I thanked him and hurried to my hubby.

I didn’t think much of it at the time, and I did tell my fiancé about it and got his input on the situation. It’s been about 3 days and that coworker seems to be avoiding me now. To me this seems pretty obvious, but I would like your inputs as well. Thank you!