Tris sets her watch alarm (which is what people had to do in order to wake up before smartphones) and goes to sleep.
Tris wakes up a sentence later and goes for a stroll outside.
Tris runs into Tobias (not literally), and he tells her that he wants to take her on a date.
Tris and Tobias climb on top of a big metal structure and share a non-alcoholic beverage or two. They decide to hash out all the uncomfortable details of their relationship, like how Tris thinks Tobias thinks she is a weak person, and how Tobias thinks Tris is a big ol' liar.
Tris and Tobias both apologize. And smooch.
Some clothes come off, and Tobias "pulls [Tris] against him" (5.68). Just how close are we talking here?