You could make the argument that the secret identity itself is “creepy and wrong”, and that a number of Superman’s traditional actions and methods are immoral.
Yes, the Clark Kent/Superman/Lois Lane dynamic is messed up. That’s precisely why it has been a staple of their fictional relationship for so long. Because it is messed up, and it makes for good soap opera style drama and conflict as a result.
Like the writers of many comics, the writers of SUPERMAN RETURNS weren’t unaware of this, they were relying on it on putting their own twist on it. They wanted to show some of his “human” flaws in context…in this case, carrying a torch when he should have been moving on. Superman isn’t supposed to be presented as perfect in SUPERMAN RETURNS. Far from it.
That said…
Sexual consent is not consent because neither party has any secrets from each other and neither person has told each other any lies. Consent is consent because both parties consent to a specific act in question, and are reasonably capable of doing so. There is not really a "Oh, but if I only knew this about them, maybe I wouldn't have had sex with them" element to sexual consent.
I don’t know that “Informed consent” means what famicommander has implied it means. It doesn’t mean that you get to know everything about someone before you sleep with them, or that the other person has no secrets from you, or that they have never lied to you. It means that you understand what you’re doing in a very specific context (a sexual act), and are in control of your physical actions. Which Lois very much is and was, based on the information we have. There’s no element of “hidden personality traits not being revealed” that reverses consent, it is not reliant on someone using a certain name, or even that they use their real name. These are dishonesties to be sure, and potentially deceptions, but they are not related to consent itself when it comes to sex.
famicommander talks about the Revenge of the Nerds thing, but Superman wasn’t a completely different person posing as someone else. He was himself being himself. Given the portrayal, you can make the argument that he was more authentically himself as Superman than he was as Clark, though there's a gray area there.
You can argue about whether Clark hiding part of himself from Lois is morally right, but you could argue that about Clark’s relationship with EVERYONE, whether there was sex involved or not. Clark hiding things from Lois doesn't make a sexual act she chooses to engage in nonconsensual.
Trying to paint what happens as Clark Kent creepily stalking Lois and tricking her into sex is disengenous at best. Context matters. There’s a wealth of storytelling that makes it clear that getting women into bed is NOT the point of the Clark Kent identity. Nor is the point of the Clark Kent identity to “hang around and pretend to be Lois Lane’s friend”. There’s a far more important context to the “disguise”that that.
This isn't remotely a scenario where he is pretending to be friends with Lois to get into her pants, I.E the traditional "Nice Guy" trope. They are actually friends.
Exactly how would Superman have deceived Lois into sleeping with him in any real sense?
Deceived her about his life, or his secret identity, but what is the deception that causes her to sleep with him when she otherwise would not have?
I think if you think he deceived her, you are making some assumptions a bout why Lois slept with him in the first place, which we can't really do, can we? All we know is that she slept with him based on what she knew...isn't that what everyone does?
If she’s sleeping with him because he’s hot…that’s…real. If she’s making her decision based on a less shallow reason; actual character traits he exhibits like being brave, and caring about people and using his abilities for good, then that’s not a deception either, because he IS the things he stands for as Superman. That's his real self.
I've often described fans' moral outrage over various aspects of SUPERMAN RETURNS as simultaneously overthinking and underthinking things. Complaining about Clark leaving Earth from a moral standpoint implies that he knew all the of the elements involved, makes assumptions about how he left, what happened and his control over the event, makes assumptions about what he and Lois knew about their ability to conceive a child, etc, and makes assumptions about the relative importance of why he left in its own moral sense.
And yes, him spying on Lois is kind of creepy….but listening in on an entire world isn’t? I think we’re splitting hairs at that point. There are problematic aspects to many of his abilities.