She likes to pretend that she was more upset that he had taken the showers gel than he had left her but she begged him for months and months to come back 'for Luke's sake' and that he needs a Dad living with him, that is why she is showing Keith int that role, inn the hope Brian will become jealous and go back to her!
Keith is enjoying the attention and free things her insta profile gets them and has no idea that if Brian said he would come back in the morning poor Keith would be told to pack his bags, that is not just hearsay that is a fact!