Yeeeah I don't think Valentine's day was EVER a thing for Yuri, even back home. That holiday has never really been for him, and he doesn't exactly synpathize with the spirit in any serious sense. Best decision he can make in that regard is to DO NOTHING as far as Vincent's concerned, cause he knows Vincent would not really appreciate it. He might get him a gift if someone tells him about the holiday, probaby a pair of gloves. He'll probably use the event to flirt with Mithos (since they're married) or Cherry and be sad he can't troll Elliot with it. re: Estelle he will probably just be... oblivious. GJ Yuri. Or he'll think Estelle's being oblivious.

Reverse?