Lit Why didn't Vader say anything to Palpatine during his two betrayals?

During the first battle of Death Star 1, when Darth Vader was beaten by Galen Marek, Palpatine openly goaded him into killing Darth Vader in earshot. After Galen's death, Darth Vader did discuss with Palpatine about the rebels, but he did not say anything about his earlier betrayal at all, and Palpatine casually kept quiet as well.

Years later during the last battle on Death Star 2, when Luke defeated Darth Vader, Palpatine did it again, but Darth Vader simply sat there and remained silent. When Palpatine subdued Luke, he got up on his feet and stood beside Palpatine quietly, and had Palpatine not tortured Luke, Darth Vader might have still remained loyal to him.

Why didn't he just ever ask Palpatine why he's trying to replace him, when he's already strong enough to do all his work for him?

 

Vader kinda knew what he was in for when he signed up for Sithdom.

 

Yeah, it's no different than what Palpatine did to Dooku, and Vader was right there for that. Then there's the fact he himself was planning on betraying the Emperor so you know...

 

We all know Vader rolled his eyes every single time it happened.

 

The Sith always betray one another.

 

I found it amusing to imagine Vader trying to have an emotional talk with Palps.

"Why you always trying to replace me, man? We go way back, I thought we were boys, man. Why you do this to me? Don't I get **** done?"

Yeah, Sith don't talk things out.

 

Palpatine would give him the typical Sith response.

"The moment you become weak enough to be killed by another, you deserve to die and be replaced."

Basically, if Luke/Starkiller was powerful enough to defeat Vader, then he was more worthy of being a Sith than Vader. If Vader was defeated, he no longer deserved to be a Sith and the being that was strong enough to beat him deserved to take his place.

The Sith are all about survival of the fittest.

 

To be honest I found this hard to swallow given all of Anakins's emotional responses, EPIII Anakin would give to Sidious a so lenghty nagging that most likely Sidious would throw himself down a 280 mile shaft directly into the main reactor of the Death Sta.