Names, Nonsubstitutivity and the Tanney Puzzle

Most people would accept as true

1) Lois kissed Superman before she kissed Clark Kent.

but would reject as false

2) Lois kissed Superman before she kissed Superman.

We should note that even a linguistically competent individual who is well acquainted with the movie and who is fully aware that Superman just is Clark Kent would be willing to accept 1) as an accurate description of part of the action. Julia Tanney accepts this too, but is then struck by an apparent anomaly. She writes:

Normally, I would be very sympathetic with the claim that there was a time, t1, at which Lois kissed Superman but not (yet) Clark Kent. I note however that the sense in which Lois (at t1) had not (yet) kissed Clark Kent would be the same as that in which Oedipus, although having slept with Jocasta, had not slept with his mother. But Jocasta hanged herself and Oedipus gouged out his eyes because there was no question for them of not accepting substitutivity.

Apart from the change of dramatis personae, the apparently only noteworthy difference between the kissing claim 1) and

3) Oedipus slept with Jocasta before he slept with his mother.

is that less clothes and more action are involved, yet somehow, intuitively, we take 1) to be true and 3) false. So this is the Tanney puzzle, and the challenge is to find a plausible rationale for this difference in truth-value assignment. That is what I attempt in this article