Some companies have rules about not fraternizing, because it creates tension in the office. I can see the point, but I also think that if you find love at the office, it's crazy not to pursue it just because of company policy. When you reach the end of your life, which would you regret more: having broken policy and found love, or having upheld policy and lost the chance at love? To me, it's no contest. If you break up, of course, it's hard to continue working together. Decide what you want your new relationship to be. Be very specific about your new boundaries--for example, don't argue about your former relationship at work, just focus on the task at hand. Once boundaries are clear, you can get through the awkwardness and have a functional work relationship.