She doesn't believe them

(Originally by Voltros)

Lilly: Oh no you don’t. I know what you’re trying to do.

She says this while pointing at Alex and Claire. They try to play dumb.

Alex: Whatever do you mean?

Lilly: Remember when you guys said it was International naked day last week?

Claire: (mumbles) I’m surprised you do.

Lilly: The only one that was naked was me. I was naked at the mall for a whole two hours before Victoria found me and told me it wasn’t. Well, I’m not falling for it this time. I’m getting dressed.

Lilly turns around, which gives Kate a perfect shot of her ass and goes back upstairs.