Movie spoiler if you haven't seen the movie!
First, let me say I love romantic comedies. Humor while falling in love, who wouldn't love that? However, The Back-up Plan something to be desired. I was going along with the story until the moment after Zoe and Stan make love. When she confesses she's pregnant, he states that she lied to him.
She really didn't lie. She omitted to mention the fact, but is that really a lie to someone she hasn't known that long? They'd only met each other a few weeks ago so would it have been better to have blurted out as soon as he'd asked her out, by the way I'm pregnant? It made the hero seem like a wuss to me. It would've been more realistic had he said something like "wow, that's a lot to process."
Another scene that rubbed me the wrong way was when Stan mentions he takes classes at night. Naturally, Zoe asks why he didn't want to tell her. Then, she says, "You lied to me. I lied to you." REALLY?
The movie took a bunch of "easy outs" to lengthen it instead of using the inherently built-in comedy of a newly pregnant woman who is falling in love with the man of her dreams who just happens not to be the father.
Have I opted for the "easy outs" in my writing? Certainly and when I've caught myself doing that, I include a note to myself to go back and work on that section. It does a moviegoer and a reader a disservice to go with what seems easy when struggling through what's hard rewards everyone with a more emotional experience.