You didn’t know that the mansion you were moving into house with a dark secret. How possibly could you know? Your grandmother said that the house was in your family for centuries. You obviously didn’t expect anyone to live there.
We’ll live might be the bad word for what was happening.
Because Aemond wasn’t particularly alive. He was well… resided there. In the mansion of your ancestors. Lucky you. Really.
You wanted to leave as soon as you found out what he is. Of course. But desperation for finally living alone… well… without your family won instead.
And it wasn’t as bad as you had thought it would be. Besides Aemond’s rather drastic diet you haven’t had any trouble with him.
He wasn’t so happy to share him home of course… but as soon as he found out he can steal few bites and taste your blood on his tongue he started to act more like a cat than a bat.