By the time he figured out what she meant, she was on her way out the door and it was too late to stop her. He didn't think it sane to follow her. What would he tell her? That he was too cowardly to make any decision about their relationship at the moment?
There was a lot to consider and if he was being honest, he was not ready to face it yet. He poured himself a drink and sat down in contemplation. What was worse? Being stuck in a relationship because of a child or letting his child know his parents were not together?
There was nothing wrong with parenting their child without being in a solid relationship, as proved by Avery, Damon and Angel, but they were different. They loved each other. It may have taken them ages to confess it and get together but deep down, they had always known it.