There's no harm at all in going along with the play, just don't take it too seriously. Ren Fairs and such are really no different from playing cowboys and indians when we were kids and it can be kinda fun to throw the seriousness aside and just play now and then. People that can't just let go, suspend their disbelief and have fun really shouldn't waste their time at these things because they certainly aren't going to have much fun unless they're sadistic bastards that enjoy ruining everyones fun. It good to be able to suspend disbelief and criticism now and then for the sake of just being entertained. Remember, life is too important to be taken seriously.