There are numerous reasons why someone might decide to take a DNA test - to check their paternity, to learn more about their family history, or perhaps just to cure boredom.
The latter was the reason one couple decided to take a test, thinking it would simply be a bit of "fun".
However, the results received would haunt them for months to come.
While the woman, aged 27, was excited by her findings, learning interesting new things about her ancestors, the unnamed man, 26, wasn't quite so happy with his family discovery.
He has since taken to Reddit to share what he found out, claiming his partner broke up with him because of it.
He says the results uncovered a very dark family secret and his partner simply couldn't get over it.
The post explained: "A month ago my girlfriend and I thought it would be fun to do the DNA test offered by Ancestry.com to learn more about our family tree.
"They really give you a lot of info and it took a while to go over.
"We were having a lot of fun with it but then I found something out about one of my ancestors that has now caused me to lose my girlfriend.
"There were a few names in my family tree that I did not recognise and after doing some research it turns out that one of my ancestors was an infamous serial killer."
Understandably the man was horrified by this information and went to his family to find out what they knew about it.
It turns out that they did, but have tried their best to disassociate the family from this person.
His girlfriend was clearly disturbed by the discovery, but he assumed she'd get over it eventually.
Unfortunately, he was wrong.
"This weekend my girlfriend wanted to meet to have a serious discussion with me," he continued.
"[She] broke up with me because she could not deal with the fact that I'm related to a serial killer. She told me that she loves me very much, but explained that the fact I had the same blood as someone so evil has made her look at me differently."
After this revelation, the man asked the people of Reddit if they had any advice on how he could win his girlfriend back.
People were stunned by the woman's behaviour and were quick to tell the man he was better off without her.
One person commented: "If she let ancestry.com results come in the way of your relationship, her foot was already half out the door and she was just looking for an out."
Another replied: "She was either looking for an excuse or she was a complete moron. Either way [you're] better off."
What do you think? Let us know in the comments below.
