[ occ: sorry for the delay! holiday rush hit sooner than expected. ]

"Vexing de Riva." The introduction is offered without hesitation in exchange for the bottle. The first taste just touches his tongue - identifying what it is, and if it could kill him or otherwise make his day difficult - but he doesn't taste any obvious poison. So he takes a real swallow from it before he offers it back to Athénaïs.

"Are we drinking for an occasion or just because you had a bottle?"