We are deciding to have sex

So me and my boyfriend have been dating for almost a year and me and him have been talking about going to the next step but the only problem is that we don’t know where to do it at I have three younger sisters at my house and they always want to come In my room and I don’t have a lock on my door and my boyfriend has younger siblings of his own and don’t have a Lock on his door and I feel like it might be an awkward topic to bring up to my parents saying I want my boyfriend to come over because they might think somethings up I mean their supportive and all but idk what to do