What did his father do to his mother for yall to be scoffing at it?
Ian's father, the former lord Sheleg, using the alias Ain, seduced Ian's mother, a southern woman and left her pregnant. Because in the south they believe in chastity before marriage she truly thought he'd come back and marry her eventually, but he never did because in the north is normal to have previous sexual relationships before marriage. Ian and his mother lived ostracized and in poverty because the north doesn't accept illegitimate children. Ian told his mother to accept that his father wouldn't come back and the one time she actually accepts it she loses all hope and kills herself.
Oh sorry I thought you were talking about Ian... Yes for Michele's parents there's a huge spoiler from the novel so read that only if you REALLY want to know.
SPOILERS
Ian was Michele's father sex slave so when Michele says his father never had any other mistress outside of his mother and no other heirs come forth when he died it's because of that. So when Michele says "I want to be just like my father who never betrayed my mother" he's talking about a rapist, but he doesn't know anything because he wasn't even alive or barely a newborn when that happened and nobody told him anything about the family's sordid deeds.
Any good transmigration/reincarnation bl?
https://www.mangago.me/read-manga/kirawaremono_no_tenisha_wa_demodotta_isekai_de_dekiaisareru/ This one is a good one,short but good since it touches niches topics
"OH NO! Only one room"