Apparently, according to at least two supervisors, "The place that's hanging up on you" is indeed an acceptable response to the question, "I know where your company's at; where are you from?"
Having a conference with Neighbor on the topic of who, exactly, it is that one of his friends and I are plotting evilly about, a "mystery man." Neighbor is aware that I've got a thing for Darkside; for some reason in this conversation, he discounted Darkside because he already knew I liked him. I laughed and finally gave him the first letter of the first name; Neighbor slapped his forehead in the classic "Gosh, that one was right in front of my nose" thing.
Neighbor did comment that when I am late in the mornings, Darkside does not show in the labs for quite a while longer than he usually does.
I have noticed that ever since I started heavily hanging out with Neighbor, Darkside has not said Neighbor's name, in the same way that he does not say Dave's name. Neighbor generally greets Darkside whenever Darkside wanders into the lab; lately, Neighbor has not been doing so because Darkside has been sending some very odd vibes in Neighbor's direction.
I have to be very sure to spend enough time with Darkside, now that I know he's noticing that I'm spending time with people other than him.
Basically, I'm going to be useless for a couple days before I get my mind around the concept that Darkside acting jealous is not just all in my mind.
It remains to be seen, though, exactly *why* he's been acting that way.