Kati

From Rom Com

All the beautiful things in life are false.
Kati is the cousin of Aimee and locked in competition with her friend Alex. She and Alex come up with a bet to see who can seduce more people, leading her to seduce Nick, Dylan, Hallie, a horde of other people, and eventually Alex himself. Kati's tentative name is Emily.
Kati appears in the following scenes:

Opening
Alex and Kati's Bet
Girl Talk
Invitation
Graveyard Seduction
Photo Montage
The Party
Hallie's Cheating
Kati/Dylan Seduction
Finding the Pictures
Dinner Sincerity
Alex/Kati Moment
Climax
Alex and Kati's "Reparations"
The End (Everyone)
The End (Alex and Kati)