Gavin has built up this tough-guy look, and it's become a shell that he stays glued to. He never cries at books or movies, never cries at songs, never holds Ray's hand at work, never shows any extreme emotion. But that shell cracks when tears form in his eyes and he shrugs and whispers "Okay then, it's done." and leaves Ray's apartment.
It cracks once more when he puts Ray's CD into his laptop and he cries.