Jack was sitting close enough to the line to hear that humming. It took a minute for him to recognize it, but when he did he looked up. When he saw the brainy brunette, he attempted to catch her eye and gave her a wave.
Any hard feelings that he might have had had faded by now. When it came down to it, he had respect for Fred and wished her the best, even if he was a little bit relieved that her hotheaded boyfriend wasn't here to attempt to start trouble.