Romeo doesn't want to leave the Capulet's property, so he ditches his friends and hides out in the orchard behind the Capulet house.
Benvolio and Mercutio try to find him. Unaware that Romeo now has the hots for Juliet, they shout lots of filthy things about Rosaline hoping that Romeo will come out to defend Rosaline's honor. No such luck.
Eventually they give up and head home.
We interrupt this program for a helpful reading tip: Worried that your copy of the play divides scenes differently than we do here? Don't trip. The division of acts and scenes varies depending on which edition of the play you're reading. Some editions of the play (like the Folger edition, the Riverside Shakespeare, and the MIT online edition) cut off Act 2, Scene 1 at the end of Benvolio's line (quoted above) and give the famous balcony scene its own section (Act 2, Scene 2). Some other editions (like the Norton Shakespeare) include Romeo and Juliet's famous balcony scene in Act 2, Scene 1.