A woman discovered that her father is actually her step-uncle in her science class after a discussion on blood types, according to other students in her class.
Anya Hettich, 19, took to Twitter to explain how the bizarre tale unfolded and quickly went viral.
She said the professor held a discussion on blood and one student couldn’t work out why her blood type didn’t match up with her parents.
She told the professor her father was type O and her mother was type A, although she was AB.
A few days later, she returned to the science class and the teacher asked her whether she was confused over the different blood types.
But she announced to the room that it turns out her mother had an affair with her husbands step brother.
Another user claimed to have witnessed the ordeal too, and tweeted:
Blood type is based on the presence or absence of the A and B antigens in red blood cells. Blood type A has only the A antigen while B has only the B antigen. The AB blood type has both A and B and the O type has neither A nor B. Biological parents donate one or two ABO genes to their offspring.