Though cheating is a complicated issue because people have different definitions of what cheating is and cheating doesn't always mean that the relationship is over, if your partner is a serial cheater, meaning they've cheated on many (or all) of their partners in the past, that could be some baggage that has the potential to derail your relationship. "If the person doesn’t take time to figure out why they are cheating on their partners, then they may continue to fall into this same pattern in their current relationship," Heidi McBain, MA, LMFT, LPC, RPT, a licensed marriage and family therapist, tells Romper in an email exchange. "If trust is at the core of a relationship, and the person is cheating on their partner, then it destroys this trust this is at the center of their relationship."

Trust issues can cause problems in any kind of relationship, not just romantic relationships, and they can crop up seemingly at any point in the relationship, not just at the very beginning. "For many people that have been hurt in a relationship, they bring this baggage of mistrust into a new relationship in an effort to protect themselves," Dr. Ryan Hooper, PhD, a clinical psychologist and relationship expert, tells Romper by email. "Unfortunately, it almost always backfires and instead ends up sabotaging their relationship."

Though it's natural to want to protect yourself from being hurt or feeling betrayed once again, if you simply cannot seem to trust your partner, that might prevent your relationship from being successful.

You might not even know if your partner has a crush on someone else, but that's certainly the kind of baggage that could potentially impact your relationship and prevent it from being successful. "Many people have long-standing intense crushes," David Bennett, a relationship expert, speaker, and author, tells Romper by email. "It could be an old friend from high school or even someone's boss." Especially if they would act on it if given the opportunity, a crush could have a real detrimental effect on your relationship.

Many people aren't big fans of confrontations. However, conflict isn't necessarily a bad thing in a relationship, but avoiding it at all costs can be. "[I]f you don’t work through it or if you’re not open to giving opposing views or opinions, then it’s not an authentic connection, really," Silver says. "It’s like you’re just saying yes and resentments can build and things like that." If you're scared of confrontation or think it's simply easier to ignore it, it could be a big-time relationship issue.

"If your partner has an intense, drama-filled past with many people, that baggage will eventually spill over into the current relationship," Bennett says. You don't want messy, stressful relationships with exes (either yours or theirs) to interfere with the success of your current relationship.

If your partner has insecurities, whether it's something they're just personally sensitive about or something that resulted from a past relationship experience, that can affect your relationship with them as well. Silver says that jealousy, control issues, and the need for constant affirmation and reassurance can really take a toll on your relationship.

Of course, if your partner has a fear of commitment, that can fundamentally affect your relationship. "When we first meet someone, we are enamored with them, and yet we are still getting to know them," Dr. Jean Otto, a clinical psychologist, tells Romper in an email exchange. "We are projecting qualities on them, especially in those relationships where you just 'click' and it feels like you've known them forever. It takes time to really get to know someone and this whole process takes about a year and a half to two years until we see them clearly for who they are, not who we want or need them to be. People with commitment issues don't make it past this process. They will often find a reason to end the relationship when they realize that you are not who they thought you were."

Silver says that if your partner has a tendency to equate their sense of self with the relationship and if their well-being is entirely dependent on you, that could be a bad sign. "It puts a ton of pressure on the other person and then they can start to feel really burnt out and just also overly responsible for you and your feelings," she adds. "It can also really isolate the person, in a way, and it almost becomes like they’re your caretaker rather than your partner." While you probably think that taking care of each other isn't a bad thing in a relationship, being in a position where you're their caretaker or pseudo-parent isn't ideal and likely doesn't bode well for the long-term success of your relationship.

Check out Romper's new video series, Bearing The Motherload, where disagreeing parents from different sides of an issue sit down with a mediator and talk about how to support (and not judge) each other’s parenting perspectives. New episodes air Mondays on Facebook.