how old is your brother? seriously, all 3 of you living in a studio, it's not very classy of him to bring the girlfriend in for a sleep in ...with his sister sleeping next to him (and mom on the floor)...seems they should find someplace else to go. mom should be the one suggesting since she is the oldest there.

how old are you? are you older then the brother? at some point someone has to say something to him or you will all have to be one happy family with this..which honestly is kind of gross. seems like the girlfriend would complain too.

say something. someone. a studio is not the place for love life with your sister & mother sleeping next to you. would it make ptsd worse? can't say. might give you a sleep disorder. if he reacts to you saying it makes the ptsd worse then run with it