"It doesn't have to be a nightmare in there either. You know you're dreaming now." And really, Gabriel just wants to explore a bit more. Which is why he feints like he's going to acquiesce to Peter's wishes before shoving him bodily through the door.

Only, he should have anticipated Peter getting overexcited and going poof the minute he goes through. He follows through and looks around, but he doesn't see Peter anywhere. "Peter! Hello?"