People
He doesn't know he doesn't like half of you. Just let him think the half of you he likes is all of you. As long as the other half of you keeps her mouth shut, the three of you make a beautiful couple!
— Lilly Truscott

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
This is sarcastic relationship advice. The speaker says a partner likes only half of you without knowing it, so let him believe that half is everything, and keep the other half quiet. Then everyone, including the hidden self, makes a 'beautiful couple.'
Context reviewed