There’s a particular tw actor who I didn’t initially realise was trans. Playing a female character, physically appears to pass (although in hindsight there’s something about the jaw that would be more obvious a tell in rl). I wasn’t exactly paying attention when watching and it didn’t quite click initially. But there was something that stood out as ‘not right’ (not a judgment, just can’t think of a better phrase) especially about their voice. It wasn’t as deep as many males, but didn’t sound female, which is how it clicked (as opposed to say Taylor Momsen’s deep but yet very obviously female voice).
I’d imagine if younger women have grown up being told this person is a woman, about a variety of examples not just this one actor, it must be harder for our natural ‘that’s a male’ instincts to kick in.
It creates confusion and yet we are taught to over ride that confusion. It’s partly where the safeguarding risk of teaching children to ignore material reality comes in.
So I think for younger women this is likely harder, not for all younger women of course, but that with that demographic especially a small minority of tw or tm may well pass until getting intimate.
But it’s still the question of why would a person want to pass until the very last minute comes up (ignore the pun). Because if they pass until they don’t and the woman admits they knew all along and didn’t mind/were just being polite, then I don’t think that would end up well for her. Or the young woman is shocked and terrified.
I can’t see how there could ever be a reason for passing until the moment of intimacy that isn’t solely intentionally predatory. Trying to pass up until that point is itself a form of sexual violence.