What is the joke in this context from Modern Family? Here, Claire(mom) is disappointed by the rest of the family members since they all didn’t do what she’d told them to do. She leaves the place, and Phil(dad) gathers the kids. Phil: you’re mother’s right. She’s the quarterback of this family, and we need to protect her like the Blind Side did. Kid1: she just said the mom was Blind Side. Phil: well, she’s confused. Blind side was the Black kid who played tight end. Kid2: Offensive line. Phil: sorry, African-American Kid. (All the kids stare at Phil, confused.) I’g guessing there’s some football and the film “Blind Side” references here, but I don’t fully understand the joke and meaning of “tight end”, “offensive line” here. Thanks in advance!