Let me start by saying I love both my parents very dearly. Both are flawed, both have been amazing.
But my mother, increasingly in recent years although it's always been a bit the case, actually cannot seem to get a sentence out without some complaint about my dad.
I don't know how best to explain: it's just like absolutely any conversation can be steered to my dad , usually having done or suggested some fairly innocuous or even quite generous thing, being presented as his being shit. She does this to colleagues, relatives, my children ... And I think especially me.
I think my dad is a good guy: he irritates me sometimes, but only in the nature of fathers. Is she trying to tell me she's unhappy, and should I do something? Or just nod at the constant moaning from one person I love about another person I love? Or ask her if she realises how much she does this?