Funny how people aiming for lgbt representation don't mind if it is just a twist on what otherwise would be lgbt erasure. Not caring if the representation is terrible and probably just hurts them, just that it exists.
Iceman was brainwashed into being gay.
Just like gay conversion therapy was to brainwash into stopping being gay.
After years (and games) of being forced to dress as a girl to avoid being killed at a young age (superstition at his home town about same-gendered twins), and spending all that time still claiming to be proud he is a guy even if in womens' clothes (the clothes even had the male symbol), Bridget completely changes personalities in this latest game and in one of the endings claims to now be a trans girl. And that is apparently now the official stance.
Now imagine if that had been a trans guy forced to stay dressed as a girl for his safety, just to turn into a cis girl at the end of the latest game after ten identifying as a guy.
But... not the time or place for this conversation, I think.
I don't think Nightcrawler did anything wrong there.
They were just discussing how Zero's powers work, and if you add how Nightcrawler's work by opening a portal to a hellish dimension and another out somewhere else, and as seen in the episode they find this out it can be left open if messed with like Forge's machine did, it adds some interesting, and creepy, results.
Would it just not let him open the first portal? Not let him open the exit portal and leave them stuck in there? Not let either portal close properly, again?
Those are all creepy possibilities, if you think about it. Yet it would be hard not to ask what would happen, since they are the ones with the powers in question and are having a friendly conversation.
Another option:
Nightcrawler has a power, but the looks are a physical mutation. ...kinda.
At least in Evolution, as there is a scene of Mystique asking what someone had done to him, and that is kinda the only possibility I can think of (or he would originaly only assume that form later in life, like Beast does). In the comics his father is implied to have actual demon blood, but only implied, so he may also just be a demon-looking mutant.
So, if Zero's powers undo that physical mutation, making him look human... it can also be revealed that his birth form was also female. And just like Rogue can be given control of her powers with a high enough level, she can learn to switch between forms.