When it comes to families, they can often be pretty darn complicated - from overbearing parents to sibling rivalry and all other kinds of drama between relatives.

And for one family, it looks like things are going to get very messy, very soon.

An anonymous man has taken to the internet to ask for some advice about his sister, who he claims has been lying to her daughter for 22 years about the identity of her father.

He says his niece was the product of a one-night stand back when his sister was younger and wanted to have a baby with her girlfriend at the time.

However, the sister told her daughter that her father was a man she had been dating, but he didn't want a child so he moved away and she never heard from him again.

She even gave her a fake name and everything.

Scientist analyzing DNA result for check genetics and forensics science.
The lies will be exposed if she does a DNA test (stock photo)

The problem is, the 22-year-old daughter is going to take a DNA test soon in the hopes of tracking down her dad.

The brother knows that if she does this test, his sister's lies will be exposed and he's encouraged her to come clean before it is too late.

In a post on Reddit's Am I The A**hole forum, he explained: "Am I the a**hole for telling my sister it's too late to keep entertaining the lie about her daughter's paternity?

"My sister is bisexual and 22 years ago, she and her girlfriend at the time were trying to have a baby. No sperm bank would take two broke college students seriously so they decided to separately hook up with two different guys they would meet at a bar.

"At the time I thought the idea was so stupid but they didn’t really care. My sister got pregnant, her girlfriend didn't. They both raised the baby until she turned two when they broke up. Ever since my sister has been raising her alone until she got remarried to her husband when my niece was 10."

He continues to say that his sister no longer talks about that "phase" of her life with her girlfriend, especially as their parents did not approve and made the whole family swear they wouldn't tell the child the truth about her biological father.

"I was sixteen when all this was happening so I didn’t really think much of it," he added.

"My niece is now 22 and is planning on taking a 23 and Me test to find her dad. My sister gave her a fake name (she doesn’t remember the name of the guy she slept with) so her lies are about to come unravelling because obviously, the guy has a different name.

"And if my niece speaks to him he’ll obviously confirm my sister was a one night stand and they didn’t date for years. My sister plans to tell her daughter he’s lying and was ashamed because he hid a girlfriend from her and that’s how she’s going to explain it off to her daughter. But I think it’s too late to keep lying.

"I think it’s because her husband is conservative and wouldn’t accept her seriously dating a woman, planning a baby with her, and even naming my niece after her girlfriend deceased mother. My sister says I’m an a**hole for not wanting to back her up after keeping her lie for all these years."

The Reddit post has garnered a lot of attention online, with many people sharing their thoughts.

One person said: "NTA but I’d stay as far away as possible from this big ole bomb. Why can’t she just say she had a one night stand for fun and nine months later, there niece was. That’s not even a lie. She doesn’t have to talk about the relationship she was actually in if she doesn’t want to."

Another wrote: "She can say he's lying until she sees blue in the face, the test results will speak for itself. It is too late for lying."

A third replied: "Well, I don't think YTA necessarily, but why are you hell-bent on butting your head in? I would back way way way off even if you disagree. When you have your own kids, you can screw them up however you like, but your niece isn't your daughter.

"If the niece asks you, refer her back to her mother. The niece is a grown-up and will figure it out. AND - let's say a silent prayer for the biological father who probably doesn't know she ever existed and is about to get his life blown up. I really don't like your sister. How would you feel if you found out you had a 22yo you never knew about."

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