Are there any good reasons to stay friends with your ex? Sure. If neither of you has ulterior motives like the ones listed above, and if your friendship doesn’t interfere with your current relationships—a good litmus test is whether you're comfortable hanging out with your current partner and your ex together, and whether your ex’s partner is comfortable with you—it could very well work. Ulterior motives can be sneaky, though—our minds have ways of disguising them as more innocent aims. So make sure you are being honest with yourself about what your true intentions are.