My opinion:
I think it depends on how their relationship is and what they're competing for. For example, my best friend and I compete all the time for trophies (of game we make up) and I feel like considering they're just games it wouldn't be serious. But, if it were more of a serious situation like a chance to win 1 mil, then it would be an actual competition. In the end, there should always be a way to solve problems between friends unless it was something completely unforgivable.
