First time

The first time is always terrifying. Emotionally and physically. You one: never know if they're only using you for that one thing. And two: you're scared of how much it'll hurt.
I've had the sex talk with this one guy. He wasn't pushing it too much, told me that if I don't feel like it, then we don't have to. But he's just talking to me casually and sometimes flirts with me. I don't know..
 First time experiences.. I need some advice..