Living in the same house with one's ex-wife

I divorced my wife 3 times not in 1 go. We are living in the same house as we have an 8 year old son. Me and my ex wife dont see each other in the house. If she is upstairs I am downstairs and vice versa. Its a rented property. She has said after her iddah she wil move out. Is it ok that we are living in the same house? Will we be sinful? Our son is becoming a hafiz so thats why I have not moved out from here as I wake him up in the morning and sit with him whilst he prays. He is used to being with me. He doesnt learn properly with his mum.