Wild goose chase

I'm Mercutio. I'm Romeo's BFF and I never back down from a fight. And you know what I think?

Nay, if thy wits run the wild-goose chase, I have
done, for thou hast more of the wild-goose in one of
thy wits than, I am sure, I have in my whole five:
was I with you there for the goose? (2.4.70-73)

Who Said It and Where

This quote comes smack dab in the middle of a couple of fellas talking trash and telling some of the dirtiest jokes in Western literature. You know, just a few bros chillin' together. Those bros just happen to be Mercutio, Romeo, and Benvolio from Romeo and Juliet.

The three guys of the Montague posse never miss an opportunity to mock the Capulets—or each other. They begin by taking a dig at Tybalt, and then move on ribbing each other. Without ever really announcing it, the guys have a joking match see who can outwit the other.

Mercutio says if the jokes are just going to run wild to any topic, he's done. Romeo is better at joking than he is anyway, and he'll lose, he claims. Romeo says Mercutio is really only good for jokes. He can't do anything else.

But don't worry, this is all in good fun. The whole exchange is downright hilarious to them and the audience for that matter.