Maybe you mean this one http://www.mangago.zone/read-manga/sorenari_ni_shinken_nandesu/ ...?! it had the same type of event that you mentioned in the later chapters
I also read it few days ago the mom was so focused on the partner child that the poor baby was crying n i really hated the mother
I forgot the name but the dad was working on a restuarent n the seme was a regular customer also a friend of the owner
YES, THIS IS IT! OMG THANK YOU VERY MUCH!! Also, yes, I confused this event with another astory XD
Maybe I’m confusing this with another story, but idk why I remember Honami chan going to meet the new husband of her mommy and his kid and feeling out of place because no one gave her proper attention, not even her mother. Is it from another BL story or does this ring also a bell to this story? Tried to look for those pages, but I couldn’t find it.