No. They're not. I felt like it was pretty clear - she had confessed to the priest that she was in love with him but had never expressed that. In that last act, we find out that he loved her too, but had never expressed it. She jokes that she wishes they had been having sex the whole time. The tension is that her presence in the home, in taking over Mary's role as mother during her "virus", has created the impression that she is the wife and mother or would like to have been. Aunt Pat can see it and needles both women about it. Mary can also see it and that's why she wants to get rid of her now that Seamus' body has been found.