Mack has the unenviable position of Kevin's best friend, which seems to consist of putting up with a constant stream of idiocy. He must also put up with Kevin's habit of calling him "Mack Daddy" - a nickname which Mack despises. Mack has repeatedly and sometimes fiercely demanded that Kevin stop calling him that, to no avail. He does derive a certain grudging pleasure from making subtle barbs at Kevin's expense, even though they go way over his head. On some level, Mack must genuinely consider Kevin a friend, as he has been known to unselfishly help him out from time to time - for instance, he helps Kevin get back on the team after he's kicked off for deliberately throwing the game (he was doing an assignment for O'Neill's class in which he had to fail at something).

He dates Jodie Landon, and although it seems at first that their relationship is almost by default since they're practically the only two black kids in school, it develops over time. Jodie indicates at one point that they have even had sex.

Mack owed his father some money at one point and took a job over the summer as an ice-cream truck driver. The kids (particularly the Griffin boys, Sam and Chris) treated him like crap and he hated the job, but was able to pay back his father and made some extra money to take Jodie out. This marked the point where their relationship became more "real" and less for show. Jodie claims Mack is not good with money (he had been behind on his allowance since third grade), but he presumably changed his habits after a while and plans to go to business school.

Mack's family is not wealthy, and he depends on a scholarship in order to get into Vance, the college of his choice. He succeeds and is able to go, but it is not clear whether the scholarship is for football or academics.

Along with Jodie, Mack is elected to Homecoming Royalty every year, but seems to resent the insincerity of it less than she does.

When Jodie is pressured by her father to attend a different college than the one she wants to go to, Mack steps in without her knowledge and convinces Andrew Landon to let Jodie go to the school of her choice. Jodie is overjoyed with Mack at this show of support.

Mack is easily the best student on the football team - he's the only one with an average above "C", and the only one who could actually be considered intelligent.