(last edit, I promise!)
[The surprise on his face is obvious as he looks up to Euphemia's face. After Cornelia, she's the last person he would have thought crossing path with in this place. He stands up to great her, studying her face very carefully, wondering if Cornelia spoke of their date and how much she told her younger sister about it.]
Miss Euphie! I'm...surprised to see you in here.
[He smiles softly, invitingly at her. Despite being on shaky terms with the older princess, Oliver had find Euphie's company pleasant and so he pulls a chair for her]