You don't necessarily have to bring up the dream (in fact, Zimmerman suggests you don't), but you do need bring up any issue that might be manifesting in those dreams. Even if you aren't flirting with anyone in your real life, having a cheating dream gives you an opportunity to take stock of your relationship, Zimmerman says. "How happy are you, really, with your sexual relationship with your partner? Think about whether there's stress around sex, whether you’re happy with the frequency of sex in your relationship, whether you're expressing your desires and having them met, and whether you feel good enough about your partner that you want to be having sex together," she says. If you're unsatisfied with your sex life, dreams about cheating could be a symptom. So, again, you'll want to chat with your partner to figure out how you can start feeling more satisfied.