The number of siblings you have determines if you're a cheater.

You may want to start asking your date how many siblings they have.

How many siblings do you have?

Because that number may determine exactly how likely you are to cheat on your partner.

A survey conducted by SeekingArrangements.com of 430,000 people has ranked those most likely to cheat according to the number of siblings they have.

Here are their findings:

Only children are the most likely to cheat (33%).

Those with four of more siblings are the second-likeliest to cheat (24%).

Those with two siblings are the third-likeliest to cheat (20%).

Those with one sibling are the fourth-likeliest to cheat (14%).

Those with three siblings are the least likely to cheat (9%).

“Everyone automatically assumes that it’s the man that you have to keep an eye on when it comes to infidelity, when you really should be checking if he has any brothers or sisters,” site founder Brandon Wade said in a press release.

“Only children have the stigma of growing up quite lonely with the automatic tendency to fill that void. One has to believe that these habits transgress into all of their relationships, romantic included," Wade continued.

Don't say we didn't warn you.

SCROLL THROUGH the gallery for celebrities who have allegedly cheated and how many siblings they have...

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