S3·E14 Walter Under the Bridge

Tina's new boyfriend James comes over to meet the family. During dinner they find out that his father once dated Casey in high school. When James tells his dad about this, he decides to come visit. While getting ready, Casey breaks down and tells the family that Walter had stood her up one day and later dumped her. After hearing this, Harry reveals that he never gave Walter a note from Casey saying where they'd meet. So Walter didn't actually stand her up, and that's why they broke up. Casey is at first angry at Harry, but later realizes that Walter wasn't the right man for her and that Fred is.