Copy Bro: the Doppelganger in the Condo

Mom and I sleep in the bedroom and brother sleep outside at the living room while the other room in the house serves as the stock room and the computer area I sit close to the window that way if I had this weird feeling of wanting to smoke a bit I can, from where I sit its right in front of the room door and outside its where my bro sleeps on a sofa bed, some evenings he will just be sitting there watching tv on his phone while sipping alcohol but most times he lays down while watching. 

One evening or should I say early morning I went to the kitchen to boil water so I can have ramen yes I know its carb cravings but who cares people get hungry if they write, anyway, as I was passing through the living room I saw my brother sleeping soundly, so I never bothered waking him up if he wants some ramen so I can cook some for him as well, I turned around to get a bowl from the back and from there I can see where he sleeps, the thing is I saw my brother's feet dangling on the couch and I saw his head and shoulders sitting on the couch, I didn't give to so much thought anymore and thinking maybe he just needs to run to the bathroom I asked him if he wanted some ramen, the guy on the couch did not say anything, from my peripherals I saw him look at me with a blank expression, I did not bother to look back at him not that I am afraid or anything, but I just find it wierd that he didn't answer my question about the food, walking back to the room I saw my brother laying there motionless like nothing happened. It was like he didn't even bother to sit up. went back to the room Ill just ask him tomorrow.

The day after that as I was cooking in the kitchen I asked my brother to get something at the store for me I saw him go out the door to the elevator, then I went back to cooking, as I went to go check the veggies in the fridge, I saw my brother went in my mom's room all the way to the balcony so I called his name and asked if he forgot something, again there wasn't anyone answering, I went to go check him in my moms room he wasn't there so I checked out the balcony and there's no one there, then it dawned on me, that wasn't my brother I was talking to the night I was making noodles and that guy dressed in the same shirt and shorts that went in the balcony. 

A week has passed I haven't seen the doppelganger that was copying my brother, he must've found out I learned on who he really was or what he really is, the question is why does he keep copying my brother? Hever copied my mom or me, then again there is just the 3 of us in the house. If I was him I will move to another household there are a lot of families living in this building, why us? that I will never know.