I did a search and didn't see any other reviews for The Squid and the Whale, so I'll throw my 2cents in.

This is the story of a family going through a separation and divorce, and all the troubles "Joint custody" cause. I am a lucky girl and my parents have been together for 35 years, but I recognized many of the situations from my friends lives.

I totally recommend this movie, it def has adult themes (nudity and sex) and bad language, so if you are offended by this stay away.

From IMDB:
The patriarch (Jeff Daniels) of an eccentric Brooklyn family claims to once have been a great novelist, but he has settled into a teaching job. When his wife (Laura Linney) discovers a writing talent of her own, jealousy divides the family, leaving two teenage sons to forge new relationships with their parents. Linney's character begins dating her younger son's tennis coach. Meanwhile, Daniels' character has an affair with the student his older son is pursuing.

Really great performances from the cast, and a really believable story.