Why do I feel like this?

Today I was at an MLB game with my boyfriend, and I saw that a family friend (who I've always had a crush on) was also at the game. Somehow I saw him while I was with my bf getting a drink and I called out his name. He was with another girl, he looked my way and I said "hey". He gave me a weird look like he wasn't sure who I was (we grew up together) and gave me a weird "hey". For some reason I felt crushed after this, even though I've been with my bf for 6 months now.