What kind of behavior is appropriate with my boyfriend's brother

I have no siblings and i also come from a different culture. They're mexican. I'm 18. I live with them as my boyfriend is in jail for a while. He feels bad because the jail thing is sort of his fault. He's superrrr nice to me but not in a weird way. He just loves me as a little sister. I'm just wondering is like hugs, watching movies, being in his room together (he has the only room with an AC) appropriate? I say this because i have no friends here. I love my boyfriend and would never look at ANY guy that way. Especially not his brother. I just dont want any of his family to think it's weird