Hugh Grant is pretty 'watchable' in most films he does. His on-screen presence is pretty much consists of witty lines, snappy articulation and boyish / non-threatening charm - and some element of nerves.
He's got that same appeal in this movie - and with the over-the-top acting of Tom Arnold, the film has great comedic performances. Still though, it lacks a compelling story.
The simple storyline never got interesting: an unmarried couple discovers they have a baby on the way. The soon-to-be father (Grant) seems uncomfortable with idea of becoming a responsible husband and father - leading to problems with the mother (Julianne Moore). Being in presence of a reckless family (headed by Arnold) just seems to make things worst ... and the story progresses from there.
If you're a Grant fan, you'll enjoy his part in the movie. However, get ready to also discover that it isn't enough to save this movie. It's just not that fun to watch.