On their second "date" weeks later, she informs him that they're pregnant.
Can a one-night stand lead to hilariously-ever-after? In life, not likely. In life, it's preferable for children to be a product of a committed relationship than vice-versa. Yet improbability is the essence of farce, which bypasses brain for funnybone. In other words: No fetus, no film.
This stipulated, Apatow doesn't quite connect the emotional dots between Alison's considering an abortion to her decision to keep the baby, which unnerved this pro-choicer as the potty-mouthed pothead humor no doubt will unnerve many pro-lifers. Fascinating how laughter dissolves the ideological hard lines.
In truth, the unplanned pregnancy is a MacGuffin, as Alfred Hitchcock tagged the plot device that motivates characters. Look past the jokes about morning sickness and commitment anxiety and what this unpredictable movie is about is forging a relationship.
Can Ben and Alison build a bridge between guyville, where he crashes with four stoner pals, and girlworld, where she resides in the tidy guest house of her married sister? Can slacker and workaholic find common ground? Can ordinary Joe find happiness with gorgeous Georgia?
Though not the most cinematic of filmmakers, Apatow gets the audience into Ben and Alison's heads and hearts, merely by showing what the world looks like from their wildly different perspectives.
He elicits unexpectedly poignant performances from his leads as well as from Paul Rudd and Leslie Mann (his real-life spouse) as Alison's bickering brother-in-law, Pete, and sister, Debbie. As the pregnant pair try on their relationship they wonder whether all couples are doomed to the too-tight fit of Pete and Debbie.