Mixed signals from a coworker

We work in the same place, but we rarely see each other. We had a group hang out late at night after work, he looked me straight in the eyes while playing the guitar. I asked him to play one of my favorite songs, and after that, he kept watching me for three songs straight, almost without looking away. The day after, everything was completely normal.

It happened again during another group hang out: while I was listening to him play, I took a few videos of him, and I caught him smiling in every single one of them. He has never texted me or anything tho. I honestly don't know if I'm just imagining things.