Competing is one of the most enjoyable and stressful aspects of Jiu Jitsu. Going with your team at the venue and cheering for each other while fighting, being there for each other through wins and losses and getting medals is surely one of the best aspects of this.
One potential situation you can find yourself in is when you have to face a team mate in competition. This can happen either at the weight class, or even more common at open weight. This situation can go down in multiple ways.
Depending on the gym and your status at that gym you might, for instance, be required to forfeit the match to the other guy. This usually happens because you’re either an outsider at that gym (newcomer, etc) or you haven’t beaten that person in sparring at the gym, thus you are required to forfeit the match to him so that he can save valuable energy and have a bigger chance at placing. But that’s not always the case. There have been cases where the professor had to face his student in the finals and chose to forfeit the match in favor of his student. For example, Romulo Barral chose to do that at the 2016 IBJJF Europeans.
You might not be required by your professor to do this, you might want to do this yourself or the opponent would. If you guys know each other and you two are sure that one of you will win for sure because of the skill gap, you can do a gentleman’s agreement and let the other person win.
That being said, this should often not be the case. Most professors leave their students to fight it out on the mat so there’s no bad blood between them. A good thing to note is that when you face your team mate, the professor usually won’t keep the corner of either, although sometimes friends might do.
A good thing to do is, when you have big upcoming competitions (think NAGA, Europeans, Mundials, ADCC, etc), check the registered athletes list or the brackets before the competition and look at your weight class for team mates. If you have team mates on the same bracket as you, talk to your professor and make sure everything is fine and you two can duke it out on the mat.
Generally, it’s good to avoid drama and it’s best if the two of you can just fight it on the mat fair and square and have a good time. Whoever wins, you’ll just slap hands, hug each other and probably have a great time talking about it and watching the replays afterwards and you should not let competitions ruin your friendships.