Crude and Terrible
Definitely not as funny as National Lampoons vacation. There's a lot of immature humor, but nothing really eyebrow raising (or funny for that matter).
Violence (1/5): A cow is hit by a 4-wheeler offscreen, though we blood and guts on the driver later (a nearby cow licks it, ha ha...).
Language (3.5/5): Expect a lot of f-bombs and it's variants, but it's a pretty average amount for an R-rated movie. A young kid does swear a lot without reprimand.
Alcohol (1/5): A mother drinks a whole pitcher of beer at a sorority party and drunkly stumbles through an obstacle course.
Sex (4/5): Lots of crude humor about sex. Someone spray paints a penis on the family's door. A young brother teases his older brother by saying he has vagina (this reoccurs). Men and women are seen in the dark only wearing thongs (breasts seen). A son asks what a [vulgar sexual act] is, but it is not explained. There are some subtle jokes about pedophilia. A brother in law wears tight underpants and attempts to furtively flaunt his (obviously fake) bulge to the protagonist's wife. In the ending credits, a picture is shown with part of his penis sticking out of his pants. But by then you will have probably walked out of the movie. It's a skip.