They begin rowing, which becomes worse due to Susan's grief. Susan Hill of the Daily Star revealed Karl and Susan were to separate following a make-or-break holiday. Their decision leaves Malcolm devastated and he takes his anger out on his mother, but Karl then admits it was his decision to end the marriage.
Susan starts rowing due to her grief; this worsens as reported by Susan Hill of The Daily Star. She mentioned that Karl and Susan were contemplating a divorce after an important holiday. This decision affects Malcolm, who vents his anger on his mother, but Karl eventually admits it was his choice to end the marriage.