- "So what do you two say? Do you want to meet your step-cousins?"
- ―Hector Wilson to Francis and Patrick McReary
The Step-Cousins Wilson is the first comic in Season 4 of Sibling Rivalries, and is the 30th comic overall.
Hector and Maureen take the McReary siblings to meet Hector's brother Louis, and his three kids:
- Troy, the youngest child of the family, who is a very weird boy
- Adrian, the middle child, who is an average preteen boy
- Samantha, the oldest and only girl of the three children, who is the smart and girly child
♥ = character's debut
♠ = character does not speak throughout comic
♣ = character is mentioned only
♦ = character appears in a speaking/non-speaking cameo only
- Patrick McReary
- Francis McReary
- Gerald McReary
- Derrick McReary
- Kate McReary
- Maureen McReary-Wilson
- Hector Wilson
- Louis Wilson ♥
- Carol Wilson ♥
- Troy Wilson ♥
- Adrian Wilson ♥
- Samantha Wilson ♥
- Mark Sanders ♣
- This is the first comic to have Hector Wilson as a main cast member.
- Beginning with this comic, every character's ears are visible again (their ears have not been visible since "Hello, Wisconsin!"), and the pockets on their pants/shorts are visible as well. Also, the comics were more detailed (although this was more prominent starting with "The Return of Armando Vasquez").
- The title of this comic is a reference to The Cousins Bellic, the first mission of Grand Theft Auto IV.
- This is the first comic since "Frightful Football Reunions" to have both Angel Chacon and Salvador Real absent.
- Seventh comic to have a character's last name in the title. ("Sibling Rivalries: Salvador Real's Adventures", "The McRearys Get Schooled!", "Gonzales Vs. McReary", "The McRearys' Halloween Special!", "A Day With Drew Brees", "Patrick McReary: School President")
- Second time someone was called easily forgiving. ("Dodgeball Mishap")