Alice wasn't the only one who was thinking something similar, Aria of course recognized that expression, as she was the first "outsider" to join the family, and so she went through a small friend state, not that it took her too much time to develop feelings for Aster, something that up to this date she questions.
It's not like she just accepted becoming Aster's lover on a whim, it was a bit rushed if you think their relationship started not too long after they met, but before she decided to become his, she carefully evaluated her feelings.
During her whole life up to that point, Aria had many bitter experiences, once she bloomed as young lady, both boys and girls started to show interest on her, her family also tried to use her as a way to climb the ladder, the few "friends" she had revealed their true colors soon as well.
