Is it permissible for my mother to greet and kiss my daughter's husband?

A man's wife's mother and her grandmothers, from both the maternal and paternal sides, are forbidden to him as soon as the marriage contract with the daughter is concluded, based on the Almighty's saying: "and your wives' mothers." Since the wife's mother is permanently forbidden, it is permissible to greet her, shake her hand, travel with her, and kiss her. Kissing should be on the head or hand. Kissing on the cheek is disliked if there is a concern of lust. This permissibility is conditioned upon neither party developing an unnatural inclination towards the other, especially in these times when corruption is widespread.