Because her husband is ugly and evil. White Knight types (which are the majority of the guys falling in love with Celestine) tend to idealize women so they can't wrap their heads around their "pure" waifu loving such a man, especially since they also refuse to entertain the idea that she's as...
On the other hand, Maya snitching is stupid because Alicia is her future employer. Once the Duke croaks, Alicia is in charge of the family servants. Do you think Maya will have a job after that? After making a show of how Alicia can't trust her?
It's made clear Alicia's father hasn't bothered...
What turned him off was the lie! Why pretend to have big breasts if you don't? The Seeding Ojisan will seed you either way, why must you hurt his feelings by betraying his trust with lies?!