“Dean and Rory broke up”

LORELAI: Dean and Rory broke up at the dance.

LUKE: They did? I was at the dance, how come I didn’t know about this?
LORELAI: Because you’re you.

Lorelai also didn’t know, despite being at the dance as well. I don’t know Lorelai and Luke were doing offscreen, but their attention was not on the dance floor!