Steve having a thing for the armor itself is not at all the sort of thing I usually envision, or that you see very often in fic - which is a shame, because now you've made me interested in the idea (the texture/temperature contrast between Steve's hands and the metal gauntlets he's envisioning was a really nice touch).

I agree with kijikun that the rationalizations seem just a little bit over the top (not so much that Steve wouldn't rationalize in this situation, because I completely empathize with Steve's "Oh God, what if someone walked in and saw me how the hell could I ever explain this?" fears and embarrassment, but that there's maybe a little much of it - I'm not sure if he'd actually think of himself as letting the team or Tony *down* by fantasizing about the armor, even by having really kinky fantasies about it)

It's bad enough to have a thing for a common warrior,

This part threw me a little, because Iron Man's anything *but* common. He's a superhero, after all. So I'm not really sure what you were going for with that sentence. I do get and like the fact that Steve's 1930s/40s-era viewpoint sees wanting to be dominated by another man as even worse than just wanting to sleep with one, though. It's very plausible in context, considering how much gender roles played into early 20th century concepts of sexuality (like sex involving the armor, Steve having slightly different notions of sexuality/gender because of when he comes from is something else that's both really interesting and that there should be more of).

Conclusion: More armor porn! Maybe an armor porn sequel where Tony gets in on the action, too? If I could draw, I would draw you an armor porn bribe, but my artistic skills stop at stick figures.