To compensate him for the loss of his wife, Rhaenys, the Dornish had given him a… ’gift’, so to speak.
Truthfully, he didn’t care for slavery as he found the practice to be vile and cruel, and it’s the only reason he accepted it. While he couldn’t conquer and control Dorne, he could keep them under his thumb, and if that meant accepting their customs, he’d do it.
Burning the whole continent down seemed irrational.
You are like no other woman.
He doesn’t know if it’s the color of your skin or the way it gleamed in the sunset, but there’s something different about you. Aegon never paid much attention to Dornish women, or any women for that matter, but now that Visenya had gone to Dragstone, he was…
lonely.
As much as he hated to say it, you were good with Aenys, and you were good at other things too; like singing and dancing. You may have known it, but he liked to watch you when you danced in the garden and sang in a different language. He assumed it was a song from Dorne, though he wasn’t sure which one, and he knew you wouldn’t tell him.
It wasn’t like you had a good relationship with the man who controlled every aspect of your life (even if he did give you space to do, within reason, what you wanted).
“That was beautiful singing.”
He makes his presence known one day, standing in the entranceway to the garden as you jump and turn to face him, clearly embarrassed or anxious that he had seen and heard you. It’s the first time he’s made his presence known, or spoken to you about your secret activity.