Tell him that a Vday Bday is TERRIBLE! In theory, it's cute, but you'd never get to go out as a couple for a romantic Vday date...you'll be stuck at Chuck-E-Cheeze and toting around all her friends to her parties...and she'll probably have a hard time getting older friends together for her birthday, because by the time she hits 15-25 they will be out on THEIR own dates.
I mean, besides the fact that you're totally right (IMO) about the timing needing to be when she's darn good and ready and all that, maybe he'll see this as a good argument?? I dunno. Good luck. men are poop-heads!