
It leaves me with more questions than answers....

Glasses dude has a split personality and does not know it. Split personality A is the one who shows the house, B is the one who questions the new housemate about his secret. Glasses guy is finding evidence of the other but does not believe it instead he convinces himself he's not insane. He's confused and blames the new guy although (he's a psychiatrist) he should understand what's going on.
New housemate his a "catfish" (at least I believe he's either 1: making money doing this or 2: works with the police.) he disguises himself.
So we're seeing how (glasses guy) he process from showing the new guy around to being worn out patient sitting in the office telling story.
Baby he's bad news...