So I just watched Road Trip (Supernatural), and something I don't think a lot of people talk about is what a good king Crowley is.
In his talk with Cecily, we can see that she's actually comfortable with him, she's not afraid of him like with Abaddon, she actually respects him, helping him out even though he's in chains.
Crowley asks her how's Hell and she tells him that it's a mess, that nobody's doing their job (implying that Crowley actually gave demons a job and a reason to stay in Hell, rather than just constantly torturing one another and making demons want to escape). It also shows how he actually cares about the demons there and the state of his kingdom, rather than just the position of power (which seems to be Abaddon's main, if not only goal).
Crowley also understands demons and their nature better than Abaddon, not scolding or threatening Cecily for playing both sides (he actually understands her and it shows how comfortable it makes her). It gives her insight into what a king should be, that's why she doesn't think to immediately lie to Abaddon and tell her that she tricked Crowley. She thought Abaddon would understand, like Crowley has, because that's what she grew to expect of her king; an understanding of their double sided, two faced nature.
This is also what makes him so confident that the demons accompanying Abaddon won't attack him. It's because he 𝘬𝘯𝘰𝘸𝘴, he knows that they're afraid, that they're not completely loyal to her, they're not loyal to anyone, 𝘵𝘩𝘦𝘺'𝘳𝘦 𝘥𝘦𝘮𝘰𝘯𝘴, they're only loyal to themselves and their interests.
That's what Abaddon gets wrong, and what makes Crowley such a good king. Abaddon believes that she could control demons under an iron fist of chaos and cruelty. Crowley knows that there needs to be some good PR and a general understanding of their people, that along with (obviously) fear, in order to maintain that position.
