How do I deal with my partner’s very extreme mood swings, knee jerk reactions and short temper?
tl;dr. Put it into a larger context, agree on a set of guidelines for acceptable behavior and communication.
Extreme emotions are never a good thing in a business setting, especially among partners. There’s an unwritten agreement among a leadership team that no one will go outside certain bounds of anger, mutual respect, and patience.
Usually when this happens there are other issues like lack of trust or perceived unfairness. In a partnership, often one member feels that they are doing more than the other(s), possibly feels incompetent and is trying to hide it, has personal issues or possibly several other problems.
The best thing to do is to lay it all out, talk about it, figure out definitively how to stop it. Don’t let it go on. Honestly discuss what is happening on both sides, and reinforce your desire to work with each other. If that doesn’t work, changes are needed before you damage the business.
How do you know?
I’ve stepped into the CEO role at several companies and have seen the emotional pain it causes founders to let go of the control and lose recognition. The problem usually resolves itself over time with building trust and paying proper attention to it, but not always.