Which line in this excerpt from act IV of Shakespeare's Romeo and Juliet best reveals the dramatic irony of the scene?

NURSE: Mistress! what, mistress! Juliet! fast, I warrant her, she: 

Why, lamb! why, lady! fie, you slug-a-bed! 

Why, love, I say! madam! sweet-heart! why, bride! 

What, not a word? you take your pennyworths now; 

Sleep for a week; for the next night, I warrant, 

The County Paris hath set up his rest, 

That you shall rest but little. God forgive me, 

Marry, and amen, how sound is she asleep!

I must needs wake her. Madam, madam, madam! 

Ay, let the county take you in your bed; 

He'll fright you up, i' faith. Will it not be?

(Undraws the curtains)

What, dress'd! and in your clothes! and down again!