How to tell someone your not a virgin?

I want to tell my best friend that I lost my virginity he's a guy I'm a girl. But I don't want him to think wrong of me, or think I'm trying to make him jealous (because I used to like him) but I want to talk about it to someone and he's the only one I trust. But how can I tell him? How can I randomly just tell him that without being awkward? Thanks