Most of us think that cheating is the ultimate act of relationship betrayal.

But let's get real -- people don't just suddenly decide to trash their marriage vows like that out of nowhere. They don't go to bed 100 percent bed faithful and then wake up with adulterous morning plans.

Instead of a sudden, shocking downpour, the truth is that infidelity is actually a storm that brews slowly.

Usually, this starts with dozens of mini betrayals. Things that occur in your marriage that slowly but surely crack the relationship's foundation.

Some of these are obvious -- lying to your partner, openly flirting with a co-worker, talking to your old high school flame on Facebook way too much. But some betrayals aren't so overt.

And it's these less obvious betrayals that actually do the most damage. Why? Because they let you form destructive habits that slip under your partner's radar. And those acts quietly open the door to major acts of betrayal that can lead to divorce.

So, what exactly are these mini betrayals? Here's the list:

1. You have secret relationships.

Almost everyone has a relationship outside of their marriage. Exes we're still friends with, co-workers we laugh with, best friends we share our deepest thoughts with. That's all fine and healthy. But problems arise when you use those relationships to fulfill emotional needs not being met in your marriage.

How do you know if you're doing this? It's easy. Ask yourself one simple question: "Would I act the same with this other person if my significant other was watching?"

If you answer "No," you're likely crossing boundaries that lead into dangerous territory.

2. You hide money.

Money Magazine asked a thousand couples what they argue about most: 70 percent answered money! The way a betrayal happens in this area is pretty obvious: you hide a spending problem, you ignore a gambling habit, or you siphon money into a private account.

If you're engaging in any of these acts, take action. Seek professional help -- whether it's from a psychologist or an accountant -- and tell your spouse exactly what's going on.

3. You complain about your partner to other people.

Complaining about your partner is tricky: Anyone who says they would never vent about their spouse doesn't have one!about your mate on a rare occasion is much different from consistently talking trash about your significant other (telling people he/she is lazy, dull, boring, unattractive, an ass, etc.) Not only is it disrespectful, but it also calls into question your choices. After all, if your spouse is that bad, what does it say about you that you married him or her?

But the damage doesn't stop there. Only allowing friends to hear bad things about your spouse prevents them from seeing the good, even when it's right there. If you want to complain about your partner, complain to a paid friend -- your therapist.

4. You undermine your partner in public.

You know what I mean: That roll of your eyes, that sarcastic remark, the cheap shot you take when they piss you off -- these are small, but deeply hurtful betrayals. By doing this, you're telling your spouse that your marriage isn't sacred and that you're fine violating their privacy by airing your dirty emotional laundry in public.

This creates a shit-show dynamic to your union, a soap opera that those around you want to both ignore and watch. It's like bad reality TV, but without the obvious script.

5. You're emotionally dishonest.

Emotional dishonesty comes in all shapes and sizes. From committing to something you don't really want to do, to saying that you're "fine" (when you're actually boiling with disdain), all the way to faking an orgasm. But emotional dishonesty is often most dangerous when you use it to justify your actions.

If you're doing something that, deep down, you know is wrong, you'll try to convince yourself (and your partner) that it's right. Sometimes, you'll exaggerate or downplay the situation, so that whatever you're doing seems innocent. You know it's not.

6. You're straight up selfish.

You show it in a million different ways -- with your time, during sex, with the attention you give (or don't). Being selfish on occasion isn't a problem -- it has its own benefits. But being selfish constantly tells your spouse that you're better off flying solo.

One particularly destructive way selfishness creeps into relationships is by invalidating your spouse's feelings.