Mercutio and Benvolio still haven't figured out where Romeo is.
It turns out that Tybalt has sent Romeo a message that goes something like this: "I'm going to beat you up with my sword."
But lovelorn Romeo is in no condition to face Tybalt in a duel, right?
History Snack: Many Elizabethans believed that love (between a man and a woman that is) basically turned men into sissies. Being "effeminate" didn't mean you were like a woman—it meant you were too into women.
Of course Mercutio also uses the opportunity to take a dig at Tybalt, who takes himself and his sword fighting skills way too seriously.
Romeo finally shows up, and he's dropped the depressed "Rosaline doesn't love me" act.
The fellas engage in one of their favorite pastimes, talking trash and telling some of the dirtiest jokes in Western literature. You know, just a few bros chillin' together.
As planned, the Nurse shows up to meet with Romeo. She looks ridiculous, apparently, and Mercutio can't resist flirting with her, mocking her, and talking dirty to her.
(When the Nurse questions him about the time of day, Mercutio manages to turn a description of a clock into a graphic portrayal of masturbation.)
In between all these antics, Romeo manages to take the Nurse aside and tell her that Juliet should find an excuse to come to Friar Laurence's church—where she will be married.
[FYI: Romeo's keeping his wedding plans from everyone (except the Nurse and Juliet), including his best friends.]