While the girls are talking to him, Darcy and Bingley ride up on horseback.
They chat for a while. Mr. Darcy is trying to avoid looking at Elizabeth when he notices Mr. Wickham.
Dun dun dun.
Elizabeth sees what happens: both of them change color (one picks white and the other one picks red), and they just barely tip their hats at each other, which is the Regency equivalent of flipping each other the bird.
The girls' aunt Mrs. Phillips lives in town, and they head over there to gossip with her about Mrs. Wickham.
While all that goes on, Jane and Lizzy wonder what the backstory is with Wickham and Darcy.