[Axsuul]

If you've been on Hacker News long enough, it should have been pounded into your head by now that idea means jack squat in the long run. I've been in this situation now a few times to know now that a vesting agreement is key. Do you have that?

Having cofounders is a touchy subject and any problems arising between you two now is pretty much a guarantee that it will destroy the company in the future. If everything has already been signed and there are no vesting agreements in place, the only way to do this is to buy out your co-founder to avoid any future legal issues. Or you could dilute your co-founder as you bring on outside investment (e.g. Facebook). Either way, there will be some emotion involved. I would shoot for buying out your co-founder in some way, perhaps with a loan of some sort. It's the cleanest and most quickfire solution, especially with you so invested in it. Of course, this is highly dependent on the assumption that you are passionate about what the company is doing and that there is still a great opportunity here.

Props to you though on choosing to deal with the situation now rather than later. Good luck!