Moreover, she didn't want to diss him in the first place. She was only making things difficult for him because she wanted to hide her true feelings behind her cold front.
As expected, Zach regained his spirits once he heard that Christina was willing to forgive him. He was willing to do anything if it meant that he could earn her forgiveness. He really had wronged her. Not only had he left her on their wedding day, he hadn't even explained himself to her or tried to contact her during all this time.
Just the fact that she was willing to talk to him after all this was Zach's good luck.
"Tell me what I can do to make it up to you then? If it is something I can do, then I will surely not let you down this time."