I left home because Bill fell in love with another woman.
4 seconds sound clip from the Shadowlands movie soundboard.
You can hear this line at 00:44:21.206 in the Blu-ray version of the movie.
Quote context
[...]
- Well, you must not think I'm much of a mother, not letting her son call his father on Christmas Day.
- Oh, that. That's none of my...
- It just doesn't... It's not... It isn't what it looks like. That's all.
- I see.
- And thank you for not asking.
- What's this woman doing chasing all over England without her husband?
- I ran away. It's always a mistake, isn't it? I mean, you have to face things in the end.
- I left home because Bill fell in love with another woman.
- I see.
- He's compulsively unfaithful.
- And he's sometimes violent, and I guess I haven't loved him for years.
[...]