6. Making Assumptions
It's so easy so to make assumptions about your partner, especially if you're a jealous person. Once you start assuming things, you find yourself looking at their phone, trolling their Facebook, and all the rest of it as you fall down a rabbit hole — no good. 

How to break it: Because to assume is to "make an ass out of you and me," ask your partner if you think they're up to something that's shady. It doesn't mean you'll get an honest answer, especially if they are up to shady business, but at least you'll get credit for being an adult in this scenario.