At the end of 2.13 Best Friend, Morgan points to their respective girlfriends and says to Chuck, “This is as good as it gets.” Morgan means it in the sense that their life is extremely good and couldn’t be better. But Chuck’s smile turns into a somber and longing look. He understands it in the sense that his cover relationship with Sarah is not very good (if all they can be is best friends) and is unlikely to improve, given their handler/asset relationship.
In 2.14 Suburbs, Chuck and Sarah experience the dream of a life together as cover husband and wife, which leads Chuck to get a taste of Morgan’s ‘this is as good as it gets,’ but Sarah’s apparent coolness in bringing Chuck back to reality leads him to confirm to himself and to a confused Ellie that this is as good as it gets—he and Sarah will never be anything more than what they are right now.
So, he gives up on the relationship. For the next two episodes, Sarah is then relentlessly pursued and tempted by the sexiest and most heroic man in the world but chooses Chuck at his childish worst over “James Bond” Cole at his manly best.
This is as good as it gets.