What can I do about this guy?

When I was growing up my brothers mate would always be there. I guess he was a second bro, and I was close to his family as well as him. As I got older some feelings for him develpoed. He knew this, and I knew he liked me etc However on my birthday my mate got together with the guy. This did upset me at first I was heart broken and depressed for months obviously I didn’t let her or him know. Anyway I just went camping with him and he still thinks I like him.I guess I do but I wanna prove im over him. So this weekend were going away again and a there is gonna be a guy my age with us so how could I make the guy ‘I used to like’ jealous/show im over him??