Grim would enjoy Valentine's Day a lot. He'd go around giving flowers to people and being randomically flirty, and getting in trouble for it.
The captain has too many things to do and would forget about Valentine's Day. She'd receive many complaints about a guy stealing all the flowers in the village and singing love songs in the streets for money (that's Grim), so she'd be even more busy than usual.
Quaritch would metodically put together all the gifts, cards, flowers the captain would receive and leave them where she can find them. He would anonimously add one rose, but in no way you can have him talk about it.
