Act III, Scene IV - Imogen and Pisanio. 

IMOGEN:
I false! Thy conscience witness! Iachimo,
Thou didst accuse him of incontinency;
Thou then look'dst like a villain; now methinks
Thy favour's good enough. Some jay of Italy,
Whose mother was her painting, hath betray'd him:
Poor I am stale, a garment out of fashion,
And, for I am richer than to hang by the walls,
I must be ripp'd; to pieces with me! O!
Men's vows are women's traitors! All good seeming,
By thy revolt, O husband! shall be thought
Put on for villany; not born where 't grows,
But worn a bait for ladies. [...]
True honest men being heard, like false Æneas,
Were in his time thought false, and Sinon's weeping
Did scandal many a holy tear, took pity
From most true wretchedness; so thou, Posthumus,
Wilt lay the leaven on all proper men;
Goodly and gallant shall be false and perjur'd
From thy great fail. Come, fellow, be thou honest;
Do thou thy master's bidding. When thou seest him,
A little witness my obedience; look!
I draw the sword myself; take it, and hit
The innocent mansion of my love, my heart.
Fear not, 'tis empty of all things but grief;
Thy master is not there, who was indeed
The riches of it: do his bidding; strike.
Thou mayst be valiant in a better cause,
But now thou seem'st a coward.