Thalia/Erato - no specific ideas, except that Thalia is lonely and restless and caught in a bit of a funk, so she'd jump on any chance to see her big sis. Charybdis/Crow - maybe an encounter while he's busking? I just think they'd be ridiculous fun together. Thysa/Mania - drunken frenzy + insane mccrazypants? They should totally have a night on the town. xD