Theo was happy to not really talk to Orpheus, because whatever she said, he would have a way to one-up it. He was always the brighter, cooler, more accomplished one and Theo would never ever be able to compete with that. She would live and die a short mortal life, and Orpheus would stay young and talented and beloved forever.
And in case there was any doubt of that, Calliope returned and Theo had never seen her look happier and more delighted. When Theo had come back to New York Calliope had hugged her and said she was so glad to see her, but it wasn't like the welcome that Orpheus was getting. Calliope's special boy. Calliope's real child.
Nothing like Orpheus coming back again to remind Theo that she was actually Erato's unwanted daughter, and that Calliope had only taken her on in the beginning out of some sense of sisterly duty. (She knew Calliope loved her- of course she knew that. But it wasn't like how she loved Orpheus.)
Sitting at the table, Theo took a large drink from her glass and let them do their greetings.