I think Aya is being insensitive, She have no rights to ask whats their their relationship in the first place after whats shes done with Risa. I understand why Risa just explode like that. I mean after a month she break up with Risa she got married she have no idea how hurtful what she did. Its really okay to be friend with your ex but if they ask you whats your relationship to people around you are not oblige to answer that and you are free to choose your friend