[Calliope sits back in her chair, lest she fall out of it gracelessly. Thinking is impossible, so she goes on autopilot with what seems most appropriate.]
[A smile, and nice words. She is genuinely happy for her two bestest best friends, of course she is. It's just that there's other complicated emotions going on and she's not sure how to handle them, so she won't.]
Congratulations, Roxy! I never would have expected that, but... I'm extremely happy for both of you.
[Aaand then she decides to lay her head down on the table instead, but she's still smiling.] All four of you deserve happiness.
Umm, you too, Rebecca! You deserve happiness, too.