My business partner and criqtuer/beta reader Mike Chen got to the end of my ms the other day. In the ms, my two love interests finally get together and then the last chapter is about six months later and they're engaged. Mike said, "Maybe I'm a cynical dude, but really? Seems a bit fast."
I said, "According to the Law of True Love*, your characters already know they're meant to be together and therefore after all they've been through together (all being what happens in your book), getting engaged within six months is the proper and right step."
*Law of True LOVE, not Law of True Blood, which says that Erik the vampire/ASkars loves me.
Mike agreed to believe me, although I could tell he had his reservations. But this is something I believe in. No matter how silly the situation, if your characters have gone through a major plot together that has conspired to keep them apart and they finally triumph, then of course six months is nothing! Six months is probably conservative, in fact! Believe you me, after you read "The End" in my book, and you close the cover and you put it down (reluctantly because you loved it so, obvs) and you sigh a few times, well that's exactly when my male love interest trotted his heinie down to Tiffany & Co. and picked out the following engagement ring:
Don't pretend you haven't just spent the last 10 minutes staring at that ring like it was your bitch.
It's the Law of True Love. In fact, it's a wonder they haven't bought a house together yet! They do live together, so I suppose that will suffice until their dream home is built.