Iron Hoof thinks that just because Flash touched Twilight again (helping her up) it means Flash wanted a "romantic getaway" with her. True, Iron Hoof knew Flash loved Twilight before they went up north. Does he think Flash would declare his feelings to her when they were there? And they would go out on a date? What sort of stallion comes to conclusions like that?
I hope I have made what I was thinking clear.

Correction: Iron Hoof suspected Flash liked Twilight in a romantic sense. Also, Iron Hoof is a racist supremacist bigot bent on taking Twilight for himself. Haven't you been checking my character profiles posted as the story progresses?

It has been a while since I last them, Brawny.

Do you think Iron Hoof is gay, but strongly suppresses it?

No, I do not think so. But then again, why has he pushed Flash against the wall twice now, and he could be abusing Serving Bell for a kick (no that is ridiculous).

4493987 But Discord said, that he's "a big closet case". I kinda see Iron Hoof like Col. Fitts from the film American beauty. He suppresses his true nature, and as a result releases his inner frustration in the form of anger and unneeded domination.

Yes, and there is Discord's comment that he will like doughnuts in the dungeon. Does that mean Iron Hoof prefers sex with colts over sex with mares? And what is toilet wine?

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As for the toilet wine, look here. And as for doughnuts, I imminently thought about this:

4502380 Thank you, Hungry; and here I was seriously taking the phrase literally. And if Iron Hoof is a repressed gay; would Luna know this, as she could have walked in his dreams? And if she did, then she could know the Captain's desire for a purely social advantageous matrimonial alliance with Twilight.
And another thing: could there be other Royal Guard stallions who are in the closet? And if there are, then those stallions could have Iron Hoof figured out and kept quiet about it.

4508050 Always welcome ummm... Bax and Roby? Nah. That's just sounds a hint schizophrenic, it's not like there are two of you, right...? Right?
Anyway, back to the topic. This thing about doughnuts was a wild guess, maybe it's just some sort of prison jargon like the toilet wine or it was just Discord being Discord, either way I don't know. You can probably ask Bad seed about it.

No. In her last blog Bad mentioned, that in her canon Luna visits only dreams of foals as visiting dreams of adult ponies may bring some serious undesirable effects on their minds. Besides, even if there would be no such canon in this UA, methinks Luna kinda have enough decency to preserve privacy of important politicians and officials. At least if there are no serious reason for such intervention. And for now Iron Hoof doesn't give nor Luna nor Celestia any reason to be be dissatisfied with him.

If such Royal Guard stallions exist, then they have already become members of the Order of Silver Guard.

4509211 Let us explore this development. Luna does not walk in Iron Hoof's or Flash's dreams. Ergo, she does not know Flash is in love with Twilight, she does not know Iron Hoof's vice-loined plans for social advancement, she does not know Iron Hoof suspects Flash of loving Twilight, nor does she know Iron Hoof despises the ponys who were unlucky enough to be born below him.
Could it have entered Iron Hoof's mind that Twilight likes Flash back? How would he react if he learned, Princess Twilight told him she likes Flash to his face?

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What Princess are you talking exactly? Can't see Luna telling on Twilight, at least not to Iron Hoof. Indeed, Twilight might snap and tell Iron Hoof that that she likes Flash, but I don't see that happen either, she's to collected and to afraid to give out her little secret. But I do see Twilight telling Iron Hoof off, especially if he will be his usual asshole self.

4538976 I meaned Princess Twilight in my last comment. I imagine it will be brilliant if Twilight snaps Iron Hoof's muzzle off.

4540218 Maybe it would. But not from Twilight's point of view of course. But as I said it before, this probably won't happen.