As a couple, sometimes it's easy to fall into sedentary bliss, which can mean that the idea of going out, especially when you have to dress up, may seem particularly taxing. On the other hand, if you like the whole coordination thing, being a couple literally gives you someone to coordinate with. Now, you don't have to take the matchy-matchy thing to your everyday life, but it is the absolute best for your Halloween costume ideas. That is if you're not too lazy to leave your cozy home and…