If there's something you should never permit in a relationship, it's for someone to trifle with your emotions. Whether you've known them for two days or two decades, whether they've apologized profusely or not even once, your feelings should be considered and respected. If your boyfriend vows he'll never cheat on you again but you discover him canoodling with other women -- whether on social media or in person -- on multiple occasions, he is making a mockery of your feelings. If your friend asserts that she only has the nicest things to say to other people about you but you receive word that she has made talking behind your back a pastime, she is little more than a wolf in sheep's clothing. Sadly, these opportunists will use every manner of flattery to reel you in. They may profess feelings of love and warmth, but beneath the surface they're up to no good. And, to make matters worse, they do such a good job at carrying on with the charade that yo...