Julius Caesar duet acting.

The context of this passage is that Brutus and Cassius' relationship is falling apart. The war is going badly, and Brutus needed some more money for the war effort, but when Cassius sent it, Brutus never received it. Now Brutus is acusing Cassius of getting the money in a dishonest manner.
The significance of this passage is yet more characterization of Brutus as still desperate to find an honourable way out of the mess that he has got him and the conspirators in by doing it the 'honourable' way. Cassius has known all along that this would not work, so now it has come to the inevitable conflict between the two very different characters.
Act IV SCENE III. (lines 1-120) Brutus's tent.
Enter BRUTUS and CASSIUS.
CASSIUS
That you have wrong'd me doth appear in this:
You have condemn'd and noted Lucius Pella
For taking bribes here of the Sardians;
Wherein my letters, praying on his side,
Because I knew the man, were slighted off.
BRUTUS
You wronged yourself to write in such a case.
CASSIUS
In such a time as this it is not meet
That every nice offence should bear his comment.
BRUTUS
Let me tell you, Cassius, you yourself
Are much condemn'd to have an itching palm;
To sell and mart your offices for gold
To undeservers.
CASSIUS
I an itching palm!
You know that you are Brutus that speak this,
Or, by the gods, this speech were else your last.
BRUTUS
The name of Cassius honours this corruption,
And chastisement doth therefore hide his head.
CASSIUS
Chastisement!
BRUTUS
Remember March, the ides of March remember:
Did not great Julius bleed for justice' sake?
What villain touch'd his body, that did stab,
And not for justice? What, shall one of us
That struck the foremost man of all this world
But for supporting robbers, shall we now
Contaminate our fingers with base bribes,
And sell the mighty space of our large honours
For so much trash as may be grasped thus?
I had rather be a dog, and bay the moon,
Than such a Roman.
CASSIUS
Brutus, bay not me;
I'll not endure it: you forget yourself,
To hedge me in; I am a soldier, I,
Older in practise, abler than yourself
To make conditions.
BRUTUS
Go to; you are not, Cassius.
CASSIUS
I am.
BRUTUS
I say you are not.
CASSIUS
Urge me no more, I shall forget myself;
Have mind upon your health, tempt me no further.
BRUTUS
Away, slight man!
CASSIUS
Is't possible?
BRUTUS
Hear me, for I will speak.
Must I give way and room to your rash choler?
Shall I be frighted when a madman stares?
CASSIUS
O ye gods, ye gods! must I endure all this?
BRUTUS
All this! ay, more: fret till your proud heart break;
Go show your slaves how choleric you are,
And make your bondmen tremble. Must I budge?
Must I observe you? must I stand and crouch
Under your testy humour? By the gods
You shall digest the venom of your spleen,
Though it do split you; for, from this day forth,
I'll use you for my mirth, yea, for my laughter,
When you are waspish.