@vonny,
I agree except I don't know that it is sexually exciting to her (though you may well be on target). It is at least emotionally exciting while maybe low level sexually or not at all, and coworker seems not to listen to stuff about herself yet.
On the other hand, there is a connecting zing going on with a lot of friendships, which is why so many freak if women and men are just friends. I am sure there are a million psych studies about all this. That zing may have some chemistry from one to another, or just one, but not go for it - sort of how the world works, including thinking someone is sympatico immediately.
I've some long time male friends I can talk with - we're clearly not after each other, so while I take it one way, that coworker is going off the deep end, I get her wish to just be friends.
The question to me, is, does she want to rescue him? And then, what is that about. And so on.
I don't think it is about rescue, the poor sap (see Jackie Gleason), which puts me back into Vonny's wavelength.