Which pony's would be the most embarrassed if they got a disciplinary spanking? My picks would be Princess celestia, ms harshwinny, and Granny Smith. Mostly because of age and status.

5993418 Diamond Tiara.

5993441
I bet that one would secretly love to have one.
5993418
I would say, Princess Luna is another pick. Her whole deal was being taken seriously, to not be overshadowed by her sister, to not be treated like a foal throwing a tantrum. Just imagine her being treated like one..!

5993494 Yeah, you're probably right. I bet she dreams of it.

5993418
Chrysalis and Sombra come mind. The raw indignation from a spanking would just add to the embarrasment of being physically diciplined. Plus being made to submit or guided calmly over somepony's lap might make cheeks burn just as red as their bottoms.

5993537
Squirming out of that device looks real easy. Getting accidently pushed out by the paddles also looks easy.

Looks 100% consensual.

I now want Queen Faust to show up, scold Luna and Celestia for fighting and spank them in front of the entire court.

5993732
And then they would be stuck in the corner while the trials are still going on.

5994249
*snort* Someone please write this, I'm too lazy.

5993494
I think Luna would be 'furious' instead of humiliated for the reasons you've said.
5993418
I don't see Celestia being humiliated by it, or at least, not showing it. She'd probably take it in stride, trying not to flinch and show her strenght through it.

5997465
Of course she'd be deeply humiliated. Where do you think that anger comes from?

5997538
Well, in this thread we're talking about humiliation leading to embarassement. The kind of embarassement I'm imagining is where she's standing still taking it, unsure what to do.

Luna would react with righteous fury most likely though :p

5997601
I said celestia because she is ruler of equestria, so if she was the one being spanked until her butt was red, it would be pretty humiliating.