I was holding a door open for my coworker and he noticed me as he was walking up carrying something. He started to smile with closed lips when he made eye contact, but it widened to show his teeth as he was passing. What does that mean, especially if he rarely smiles? We hung out together once, but we stopped talking a while ago. I still have feelings for him, but have been hoping this crush will go away. He's a really quiet guy. I'm 16, he's 18.