While camping in a tent and maintaining a fire in Oppenheimer (2023), Frank shares with Lawrence and Oppenheimer his plans to get married. Lawrence offers his congratulations. When Oppenheimer inquires if the bride-to-be is Jackie, the waitress they know, Frank confirms that she is indeed his future wife:
Frank: Yeah, to Jackie. The waitress.
Lawrence: Oppie, you're right. It's lettin' up. I'm gonna go see if there's any stars.
Then Lawrence leaves the tent to go outside.
What does "It" refer to ?