Because they got different daddies. That's why.
4 seconds sound clip from the Boyz n the Hood movie soundboard.
You can hear this line at 00:53:11 in the Blu-ray version of the movie.
Quote context
[...]
- Darin!
- Get them drive-by shooters out of my living room...
- Damn! Moms be fucking with his ass without fail.
- She ain't like that with Rick, though.
- Because they got different daddies. That's why.
- Y'all got to get the fuck out.
- My brother got company in a minute.
[...]