Maybe it's the tabloid fodder world we live in that makes us think otherwise, but overexposed is not the way to go when it comes to a couple, especially on Facebook. Your relationship is not a show you're putting on for the world. It's private and likely very important to you, and you do it an injustice by indiscriminately serving up every intimate detail to your social network.
Yes, even in a world where sharing everything is encouraged, your relationship is still sacred ground. Share some photos, check into a few places together, but never reach a point where the intimacy of your relationship is diluted because you've already shared it all.
Create boundaries around your personal life. People should be able to peek in and see an outline of your relationship, but they should be left guessing about the whole story. That story is between you and whoever your dating. It's yours.
So next time you find yourself in the heat of moment, rather than sharing, keep it special by keeping it to yourselves.