Set my teeth on edge

I'm Hotspur. I am pretty ticked that Henry IV has the crown and my family's left out in the cold. So I help my dad lead a rebellion against him. And you know what I think?

Marry,
And I am glad of it with all my heart:
I had rather be a kitten and cry mew
Than one of these same metre ballad-mongers;
I had rather hear a brazen canstick turn'd,
Or a dry wheel grate on the axle-tree;
And that would set my teeth nothing on edge,
Nothing so much as mincing poetry:
'Tis like the forced gait of a shuffling nag. (3.1.122-129)

Who Said It and Where

Harry Percy (a.k.a. "Hotspur"), the son of the Earl of Northumberland, is a young nobleman who leads the rebellion against King Henry IV in, you guessed it, Henry IV, Part I. A courageous and impetuous young leader, he's got a "hot" temper, eats enemy soldiers for breakfast, and has a serious thing for "honour."

We catch up with him here in the middle of a strategy meeting. Hotspur is meeting with his posse to go over their rebels' plan of attack for tomorrow. Worcester and Hotspur will ride to meet Northumberland and the Scotch rebels at Shrewsbury. Worcester says his father-in-law, Glendower, won't join them just yet because he's still getting his forces together.

Glendower promises to meet up with them shortly and says he'll escort their wives, too, since the women will be upset when their husbands leave to fight. Hotspur, who has been looking at the map and thinking about the plans to divide the land, complains that his slice of the pie isn't as good as Glendower's. Bickering ensues. Real mature, guys.

Then, Hotspur bags on Glendower by insulting the sound of the Welsh language. He says he hopes Glendower knows English because he'd rather be a cat than a Welshman. Yikes. Them's fighting words.