In a flashback we see Astor having a fling with a beautiful younger woman a couple days before the murder. The woman appears to be the first of the two busty bikini girls who pass the reception desk in the opening scene. While the viewer assumes the girls are noticing young Leo, it could be that the girls were sharing a knowing look with Astor at the reception desk. On second viewing, Astor's reaction to the situation takes on new meaning.
Martha's first appearance on the show before season 6