- "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 31st comic total.
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")
- Adrian mentions that he likes football, and he usually plays with his friends in the park after school. There is a small chance that he could be referring to Aaron Velazco, Victor Clay, and Anthony DeoBer, characters that latter appear in TNC as Adrian's friends and fellow football teammates. He does comment in "Welcome Freshmen" that he and them go "way back".