Glenn Quagmire is the resident sex pervert on Family Guy but the Griffin family has him beat when it comes to the biggest taboo: incest. From seeing each other naked to actual sex, there have been incestuous encounters between nearly every family member. Talk about keeping it in the family (giggity).
In “12 and a Half Angry Men” Peter forces the whole family to squeeze into the bathtub until he’s no longer angry.
In “From Method to Madness” Peter and Lois embrace nudism to makes Megs boyfriend feel welcomed in their home. Chris is also naked but for a totally different reason apparently. The family plays naked Yahtzee.
Stewie and Stewie
In “Road to the Multiverse” Stewie and Brian visit a parallel universe where a two-headed Stewie makes out with himself.
Chris and Stewie
In “Long John Peter” Chris and Stewie are set up on a blind date.
Meg and Stewie
In “Brian Goes Back to College” Stewie walks in on Meg undressing.
In “No Meals On Wheels” Stewie walks in on Meg toweling off, or as he calls it “that weird butt floss thing.”
In “Extra Large Medium” Meg and Stewie fart in the bathtub but when she has vaginal flatulence, he freaks out.