Jackass, minus the potential for serious injury + Borat, minus the pointed xenophobia satire + Mrs. Doubtfire, minus the crossdressing = the emptiest calories of the year. I'd like it if you kept reading but if you were looking for a simple math-like equation there it is.
It was inevitable at some point that Johnny Knoxville would tire of going to the hospital for his art. So in spite of its "R" rating for language and occasional suggestion of penises (prosthetic, stuck in soda machines) and scrotums (also prosthetic, dangling old-man-parody-style out of some underpants), he plays it safe, with minimal chance for concussion. Instead he goes cuddly, gentle and just clever-naughty enough ("They call me Jizzy Gillespie!") to remind you that this is still a Jackass joint.
Unlike the Jackass films, though, it pretends to have something almost like a plot. Knoxville, in geriatric drag, accompanies a small boy acting as his grandson (Jackson Nicoll, Fun Size) on a road trip, ostensibly to deliver the boy to his negligent father. Along the way there are public stunts in bingo halls, strip clubs, public parks, restaurants and biker bars. None of them involve the sort of bystander mockery that made Borat so sharp and Bruno so bothersome; this is old-fashioned Candid Camera stuff and nobody's made to look foolish except Knoxville (unless you count the male stripper whose erection is covered with a sparkly penis outfit). It's funny and then its forgettable and nobody gets their feelings hurt or their buttcheeks snapped at by hungry alligators.
And for lovers of the truly confusing there are also interstitial bits of plot between stunts in which Knoxville and Nicoll remain in character to discuss the details of their relationship and their sad destination, essentially a trip to dump a helpless child into the custody of a deadbeat. Attempts are made in the direction of poignancy and tenderness, the pair bonding as the family they clearly aren't. But why? For whom are they acting? Not the audience, obviously, because we get to see what the camera sees. And thanks to this level of not-making-sense, the film takes on a pushy, uncomfortable, mysteriously wrongheaded quality that outshouts the genial trickery the audience is already in on. We don't know who the movie thinks we are during these moments, part of the inner circle of prank-makers or goldfish with five-second memory spans who'll believe any new narrative no matter when it presents itself. And we're not sure we want to be played this way, treated like just another object of a practical joke. You'd be forgiven for yelling "Stop being weird at me, movie!" even though nobody on the other end could hear your cry.