Ok, just to clarify a few things up...
The guy in question that is doing the staring is known to me. He currently works on another team, but will be joining mine at the end of the month. He is married with kids, so I doubt he's flirting with me or some kind of attraction ritual. We've spoken before, it's not like nobody talks to anyone else in the room. I don't honesty think he's trying to check up on my work load, he'd have to walk up real close to figure out what I was doing at my desk.
I'm still none the wiser, short of catching him at a quiet moment in the office and directly asking him why; however confrontation like that is not my style.
Maybe he does suspect I am trans, but it's been months since he started working here and there have been quiet moments in the office where he could have asked, but hasn't so I really don't know.