Also known as: あらあら
Ara Ara (あらあら), often spelled Ara Ara~, is a catchphrase which can be translated from Japanese as "oh dear", "my, my" or "well, well". It tends to be said by motherly or older sister-like characters.
It's often associated with Onee-Shota hentai genre or milfs in general, and is commonly used for memes to hint at a female character's sexual intentions towards a younger male.