Why does he stare with wide eyes?

So I used to have a thing with this guy but we ended things about a month ago and remain friends. I never wanted to end things but he said it was for the best. Whenever I see him I catch him looking at me with massive wide eyes like surprised look. I do try to catch him but he looks away. He does avoid me a lot. Like he was with his friends and then just got up an left where we were having a drink... but the wide eyed look happened and I caught him. This has happened a lot since things ended? I miss him too. Any ideas? Thanks
Why does he stare with wide eyes?
Add Opinion