Hiya, right so the problem is them winding each other up then.
We all understand that not everybody values the idea of having tons of friends, nor are capable of making and maintaining them, especially not being so young.
So how can you arrange your house that each of them has a space? Or can you agree a timetable = he has the lounge all morning, she has it all afternoon.
And where can you make a space that is just for you? Forget the lounge now.
I'm thinking they will be housed at some stage, as not appropriate for them to stay with you their entire lives. Until then five years or so, find a way of dividing up the living space.
I work in supported living and we support people, some of whom have autism, and this is how we do it.
Also encourage them to do their chores. Keep them a list of what needs doing, including a 'home day' where they ate expected to do their washing, change their bed and clean their room. When they move out, they need to know how to take care of their living space.