Nate had poked his head out of his room just in time to see someone else - he didn't know who - go into Daphne's room. He'd seen her journal entry and decided that watching the party downstairs would probably be more fun with the group, but also more enlightening. After ducking back into his room to grab his key so he could lock the door, Nate left to join the spying party.
Seeing the door propped open, Nate pushed it open without knocking. He saw Daphne and Audrey together, but no one else. It was still early, though.
"Hi." The heavenly smell of pizza hit Nate's nose and he stepped into the room, emboldened by his need for cheese and grease. "Can we ask the scientists for anything we want? I gotta try that."