Search Results: playing games or shy

So, I believe this to be pretty obvious, but I reconnected with someone I went to high school with. We live far away from eachother now, but I'm moving back to our hometown soon...
We text on and off all day everyday since reconnecting. Like 3 weeks ago...
Its gotten pretty flirty even steamy. (usually when one of us has been having a few drinks lol)
He's very difficult to read. Only really opens up after a few beers, but kind of seems like he acts way more interested then. I asked him once why he's difficult to get to know and he said he's just quiet. So it's an ongoing joke about him needing beers to open up.
Is that a red flag? We have chemistry but it rarely is noticeable when he isn't drinking. He's said it's kind of a shy thing but worries me. We both are adults and he certainly opens up when he's buzzed.