Emma is in her bra and panties while stuck in the boathouse with Zach, and once he notices her when she asks him if she'd really have her phone on her, he makes a somewhat mischievous smirk when he sees her bra and underwear.
As Emma notices the note that she thinks Zach has written, she walks out of the bedroom in her bra and panties, with her butt, in her underwear, showing for a split second as she walks out.
Zach flirts with Emma at some early points of the movie, to which she doesn't know if she can go along with it or not.
Zach and Emma catch Jake and Bianca, to which they are having sex on the bed. Bianca is in a cat suit, and Jake is in his underwear. No high nudity.
At some points in the film, when Emma and Zach, or sometimes just Emma, run into Bianca, she always exclaims during her explanations about having sex with Jake, and Zach, which constantly upsets Emma.