Mack was the father of Kyle McBride and Ryan McBride. He came to visit Kyle and Ryan while their mother was away visiting her sister. Mack was a great source of tension within the family. He had always favored Kyle and never considered Ryan very manly because he didn't serve in the Marines like him and Kyle, instead opting for college. At a dinner table with Kyle, Amanda Woodward, Ryan and Megan Lewis, he belittled Ryan and angered Megan to the point where they both walked out at dinner. John Reilly also played Bill Taylor on Beverly Hills, 90210.