Mom! Mom, what are you saying? You're actually defending him.
5 seconds sound clip from the Back to the Future Part II movie soundboard.
You can hear this line at 00:49:39.861 in the Blu-ray version of the movie.
Quote context
[...]
- Well, maybe you'd like to have all three of your kids behind bars, just like your brother Joey.
- One big, happy, jailbird family.
- All right, Biff. You win. I'll stay.
- As for you, I'll be back up here in an hour, so you better not be.
- He was right, and I was wrong.
- Mom! Mom, what are you saying? You're actually defending him.
- I had it coming. He's my husband, and he takes care of all of us, and he deserves our respect.
- Respect?
- Your husband! How could he be your husband?
- How could you leave Dad for him?
- Marty, are you feeling all right?
[...]