Let’s start by stating that jealousy is not a rational emotion. It sparks intense feelings like fear, envy, rage, abandonment, and betrayal. These toxic emotions can create irrational behaviors in the most practical people and can do lasting damage to a relationship. Each relationship will have its own definition of what crosses an inappropriate line. This varies by person (and gender) and is usually heavily influenced by their past experiences. Unless you are in a mutually agreed-upon open relationship, let’s assume everyone here deems physical intimacy with someone other than your partner as cheating so that we can dive into way more grey areas. What behaviors are unacceptable in your relationship? Would drinks after work with a member of the opposite sex count? Chatting with a stranger on social media? Flirting? Watching porn? Friending old flames on Facebook? Discussing private details of your relationship with a friend? Emotional betrayal can be as damaging as physical affairs and sometimes even more-so. In fact, one of the leading causes (particularly among women) that is cited as the reason for an affair is due to a lack of emotional satisfaction in the marriage. According to a recent study by the American Association for Marriages and Family Therapy, when considering emotional affairs, the percentage of couples affected by cheating practically doubles. The trouble is, emotional boundaries aren't as black and white as physical boundaries and different individuals and couples may have different thresholds for what's not acceptable. So where are your boundaries? Your partner’s? Don’t wonder if your platonic relationship with an opposite-sex friend is a problem. Asking your partner, “Does it bother you when...?” goes a long way toward showing you value their comfort and it also builds trust. Your partner’s feelings should be paramount, so invite them to share them whenever you can. Know where the lines are before emotions run high and arguments ensue. Trust is fragile, and once broken, is difficult to repair. If you know there are particular sensitive spots for your partner, you can take steps to reassure them in advance.