Back home, privacy was an easy thing to get. They saw enough of each other as it was and aside from the odd pasta party or movie outing, the members of the BAU seemed perfectly happy with keeping their personal and professional lives separate. Creating sanctuaries, like Gideon would've put it. A space where work didn't invade, even if it came in the form of the people you called family.
Marina, on the other hand, did not make privacy into an easy thing. He'd learned that quickly, first from said sexy assassin ladies who didn't think it was okay for a young profiler to be alone on Thanksgiving, and then from companions in distress and now... well. Needless to say, Reid was starting to wonder if he'd settled down in the Grand Central Station.
There was no way he was going to even pretend he wasn't home or otherwise ignore that familiar knock (in part because he really liked that door on its hinges) and so he made his way over, abandoning whatever project he'd been pouring over in the living room in favor for greeting his team mates. That were at his door. Weirdness.
"Hey..." Suspicion? Maybe a touch. Note how he's not really stepping aside to let you in just yet. "What, uhm. What are you guys doing here..?"