This is the culmination of the Wife Out of Town Film Festival. This movie is pretty good, but probably too irredeemably filthy to appeal to Mrs. Salad.
But, in addition to being irredeemably filthy, it's also very funny, and (as many reviewers noted) sends out strong pro-life, pro-family values, and pro-personal responsibility themes. Kids these days!
The premise is that Ben, an affable dope-smoking loser, falls into a one-night stand with the lovely, upwardly-mobile Alison. (She works for E!) And—you may have guessed it from the title—through a drunken misunderstanding about the need for precaution, she winds up pregnant.
Both Ben and Alison get introduced to each others' worlds. Alison lives with her sister and brother-in-law, who have a strained marriage; Ben lives with four male pot-soaked no-visible-means-of-support zero-prospect buddies, barely above savagery. Much amusement results.
Alison is played by Katherine Heigl, who—honest—I hadn't seen in a movie since she played Steven Seagal's niece in Under Siege 2: Dark Territory. I think it would have been kind of cool for Steven Seagal to show up and kick Ben's ass for getting his niece pregnant, but this brilliant idea didn't make it into this movie.
Harold Ramis has a small role as Ben's father; Joanna Kerns has an even smaller one as Alison's mom. It was nice to see both of them again, but Joanna Kerns has aged much, much better than Ramis.