We act like kids, yet we flirt?

So, I'm friends with this guy whose cute and everything and we flirt, but erm...right now we're playing tit for tat; I know childish right? So, he won't commit to me and I won't commit to me because we like flirting...erm, I like the guy and everything, but I don't want to toy with him, but be serious. I don't want it to end in a NSA relationship either, please help.