If people are having fun, and the RP is cooperative - meaning one player attempts to perform an action on another, and the one who is acted on calls the success or failure, then I don't see much of a problem. If I think your attempt at an azure way spell on me is not likely, or if I think that you will use it to meta-game me, then I won't grant you that success. Otherwise, I might flip a coin if undecided about what to do.
