Regrets

Charlotte Parker is an angel that was dating Castiel Novak. They were very happy together until he went down to hell to retrieve Dean Winchester the same time she was in charge of helping a group of hunters. Charlotte thought that not much was gonna change but it did. Cas started spending most of his time with the Winchester boys and she spent time with her charges. He ended up ending things to focus on his charges. They did end things on a bad note. What will happen when Cas comes to Charlotte looking for some help? Will the problems between the two of them come between their assignment? Does Cas regret ending things with Charlotte?