The world’s richest man, Elon Musk, is the son of Errol Musk, a wealthy South African engineer, but father and son had a falling out several years ago. In fact, Elon describes his dad as a “terrible human being.”

The falling out was caused in part by a bombshell announcement. Errol told his family that his step-daughter, Jana Bezuidenhout, was pregnant, and he was the father. That was in 2017. According to Errol, even now, his other children, “still don’t like it.” He explained, “They still feel a bit creepy about it, because she’s their sister. Their half-sister.”

Just two years later, in 2019, Jana gave birth again. Once again, her step-father was her baby’s father. Watch the video below to find out Elon’s reaction to learning his dad had a baby with his step-sister.

The Musk family tree is a bit complicated. Let’s back up to the beginning.

Errol’s first wife was Maye Haldeman Musk. They got married in 1970 and had three children, Elon, Kimbal and Tosca. In 1979, they split up, and Errol went on to marry Heide Bezuidenhout. Heide already had two children. One of them was Jana. She was only 4 years old when Errol became her step-dad. Besides raising his step-kids, Heide and Errol also had two more children together. Then, after 18 years, they got divorced.

While Elon certainly does not approve of his father’s relationship with his step-sister, he seems to like having multiple children. He already has 10, which is more than his father has.

Elon tweeted, “Doing my best to help the underpopulation crisis. A collapsing birth rate is the biggest danger civilization faces by far.”

Errol admits that a relationship with a much younger woman is “not practical.” He explained, “Any man who marries a [younger] woman, even if you feel very sprightly, it’s going to be nice for a while, but there’s a big gap … and that gap is going to show itself.”

Even though Jana doesn’t live with Errol, he does see his children on occasion. He explained a recent visit saying, “They spent a few days here about six months ago. And the kids were starting to get on my nerves. Then I miss them as soon as they have gone.”

Errol may not be done having children. He admitted, “If I could have another child, I would. I can’t see any reason not to.” He also admitted that it’s possible that he has more children than he knows about. He explained, “I have about six people, women who claim that their child is my child right now. Obviously they are opportunists.” Yet, he knows that all them might not be lying. “There was a period in Johannesburg in the ’80s that I was going out with a different woman every night. I had plenty of dates. So it’s quite conceivable that one of them could actually come back and say, ‘This is your child.’ It’s possible.”