By Alexandra Churchill for YourTango

Size does matter…just not the size of what you think.

A new study claims that women are more likely to cheat on their man if he has big balls. (Yep, you read that right.) Researchers from the University of Oslo studied monkeys, grasshoppers, and sea urchins specifically—and they found that a female is more likely to have other sexual relationships if her mate has large testicles.

The testicles of humans are one-and-a-half times larger than those of gorillas—and researchers say this shows that we are an unfaithful race by nature.

Personally, we'd like to know why they decided to study monkeys, bugs, and sea urchins to determine human behavior, but we digress. The point is that you'd probably have to have big balls to interject yourself into someone else's relationship. (Bro code, guys?)

Hungry for other bizarre facts found from cheating studies? Here are 10 research-backed findings that had us doing a double take:

1. Facebook Could Foster Infidelity
A new study published in the journal Cyberpsychology, Behavior, and Social Networking suggests that Facebook leads users to reconnect with old flings, which in turn, leads to more affairs, breakups, and divorces.

2. The French Are Big-Time Cheaters
The French are known as the world's best lovers, but they might not be the most loyal. In fact, a French poll found that a majority of men and a third of women admitted to cheating on their partners. Infidelity has been on the rise in that country since the 1970s, when only about 19 percent admitted to cheating.

3. Fakers Are More Likely to Cheat
If your partner is faking the big O in bed...watch out. It could be a sign that he or she is getting action from someone else. One study found that both men and women who faked orgasms were far more likely to be unfaithful.

4. Cheaters Love Chain Restaurants
Suspect that your partner is cheating? The first place you might want to scope out is a chain. (Yo quiero...an affair?) The infamous extra-marital affair dating website Ashley Madison asked more than 40,000 cheaters where they loved to wine and dine in secret and revealed the top 10 dining destinations to have an affair. Among them? Red Lobster, Outback Steakhouse, Chili's, and P.F. Chang's.

5. Cheaters Also Love Chain Stores
After delving into the dating habits of the unfaithful, AshleyMadison.com asked about their shopping habits. In their poll of 50,000-plus women, more than a third said they spend more money to keep up their looks for their secret lover. In addition, 27 percent said they have a secret credit card to keep their financial infidelity under wraps. So what are some of the most popular stores for cheaters? Banana Republic, J. Crew, Macy's, Ann Taylor, and H&M all ranked high on the list.

…Click here for 5 more weird facts about cheating from YourTango!

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