How do i flirt with this guy at the drive-in?

there is a group of us going to the drive in , 3 guys and 2 girls - no couples or anything, but there is one guy that i am interested in. several people have pointed out our flirting to me, saying they think he is interested and such. There is one other guy going that is pretty good friends with the guy i am interested in, so i am worried he will talk to him the whole time. My main question is how do i flirt with him in our group? I dont want it to be super obvious I like him, I just want to see if he will flirt back and how he will react