Your Best Friend's Sister Edit Meaning

1.

a stupid comeback phrase that's used for virtually everything, even if it doesn't make any sense whatsoever

Friend #1: dude! i saw your mom last night! she was hot!

Friend #2: your best friend's sister!

Friend #!: you have a sister!?

dude: what happened last night!?

dude 2: your best friend's sister!

dude: shut up!

See brah, dawg, thug life, that's what she said, 69