She was consenting to sex with someone else, the tall studly guy with the red cape.

Which is exactly who she had sex with. The fact that he's also Clark Kent is about as relevant as the fact that he likes to do crochet in his spare time, and Lois hates crochet. That is not even the same universe as agreeing to have sex with someone and consequently sleeping with someone entirely different.

Again, for them to have "informed" consent, shouldn't he have mentioned that in passing?

No. Failing to volunteer information and thereby presenting the best possible picture of yourself is not remotely the same as giving false information and thereby capitalizing on someone else's picture entirely. I don't know how many different ways I can say this.

Bond is, of course, a gold-plated asshole. Nobody's arguing that. What he does is probably comparable to not telling your partner you have an STD (which I bet he's also done regularly), or that you're actually married to a jealous prizefighter. Part of being a sexually active adult is knowing that sex carries a risk of contracting STDs or jealous lovers. Hence it is reasonable to expect that "informed" is the default state wrt to Bond's jackassery.

It is not reasonable to expect that someone you believe to be one person is actually somebody else. "Informed" is not possible in this case unless the masquerader himself spills the beans.