[Keroko]

Ehh, "planning out" doesn't mean "marry immediately." It just means that the proposal, engagements etc. will be handled earlier.

I mean, in addition to Couvert's questions to Cinque, when Couvert jokingly said she'd propose to Rebecca if she was a boy, Milhi (who only caught the "propose" part) responded with a surprised, but calm acceptance rather than complete shock. That shows that, on a cultural level, this is accepted in Flonyard.