Wow, that's pretty rough... Sorry to hear that. I had a similar issue - I had to ask one our cofounders to resign and he was one of my best friends. (He starte

Wow, that's pretty rough... Sorry to hear that. I had a similar issue - I had to ask one our cofounders to resign and he was one of my best friends. (He started another company that raised conflicts of interest) It was very difficult. Here's what I took away: 1. Be honest with your reasons for leaving: If the fit is not there, it's not there - you can't force these things. It is in the long-term interest of the company to have people that believe in the vision. Anything less will only drag down morale. 2. Be grateful that you had the opportunity to work and learn with them: There's generally two ways to spin these things, "you wasted my time" or "this will be a cherished memory." It's always better to lean towards the latter. 3. Be resolute: If you're bent on leaving, know that this is the outcome walking out of that meeting. Startups are kind of like a band of brothers, it's easy to get guilted into a compromise. An addendum to (3). Lack of communication is a common killer of startups, and it's usually built up over time, eventually leading to an ultimatum (like this). I'm not sure what the relationship between you guys are, but this can be a point of reflection / growth. If you have thoroughly thought this through, and there are no scenarios where you would be willing to stay, then that's fine. But more often then not, the points you bring up are invaluable to your peers - if they are receptive. If it were me, I would bring up these concerns prior to your resignation and see what their reaction is. If you guys don't see eye to eye on these threats, then it's time move on.