Harmony Spark

I have two bets friends who are boys, Calum and Max. Max is younger than Calum and I've seen the two bicker all the time and I really hate. I often tell them that it's upsetting me and my other best friend, Paige (who's a girl). But they still do it! They have different interests and since max is more angelic and Calum is more demonic its sort of Chaos. I really want everyone to get along cos I have a fear of disharmony and that I really care about them! What should I do??...