So here is a situation, we are facing. We are three co founders - Saun, Sam and Joel.
Saun has been discussing about starting up with Sam and Joel who both happen to be his college mates. All the three have worked together on various projects and have a good understanding of each other.
Meanwhile, Saun and Joel are in a relationship.
When they finally decide to take the plunge into the startup, a confusing situation arises. According to Sam he is at a disadvantage as compared to the other two. He believes that since Saun and Joel are in a relationship and have a better understanding with each other , he is the one who would be left in the minority in majority of the decision making.
How do we resolve such a situation.
For context, this is from my personal experience building businesses with my significant other. We've been co-founders for 5 years now (a small business, and a startup), and we were a couple for 3 years before starting our own business. Your mileage may vary!
I think Jesper's 2nd point is important: life as a couple and founders of a startup can be very demanding and will put strain in your daily life. You need to absolutely sure you both want this; there is unfortunately no way to prepare for that.
Regarding the "2 vs 1" situation: it needs not be a problem if managed appropriately. First of all, though, you all need to agree that it can become a problem so you can proactively defend yourselves from falling in a situation where your business gets hurt or where relationships between the three of you go sour (or both!).
Lastly, keep in mind at all times that you need to separate business from personal relationships.
The business goal is one and only one : to be profitable so it can fulfill its mission (whichever it is). Keep business issues in the office and personal issues at home.