4 Danielle Heaney and Nick Cameron

Danielle and Nick didn’t grow up as brother and sister. Raised in foster care, Nick Cameron met his half-sister Danielle when she was twenty and he 26.

After three weeks of knowing each other, they began a sexual relationship but were reported to authorities by their mother who walked in on them having sex. Incest in their native Scotland is a felony, and Heaney and Cameron were sentenced to nine months probation where they could not have verbal or physical contact.

They now live together but claim to not be sexually intimate. When they were last interviewed the pair were contemplating a move to France, where incest is not a crime.

3 Patrick Stuebing And Susan Karolewski Patrick Stuebing and Susan Karolewski are vocal activists for changing German laws against incest. Meeting for the first time as adults, Stuebing (who was adopted at birth) and Karolewski live together as a couple and have had four children together. All but one child has been taken from them by authorities, and Stuebing has undergone a vasectomy after serving a two-year prison sentence for having sex with his sister. The couple’s lawyer argues that the German laws regarding incest is out of date and should be lifted to allow consenting couple’s privacy. In 2008, German courts upheld the laws on the basis that inbreeding causes bodily harm to potential children. Stuebing and Karolewski still share a small apartment in Leipzig.

2 Mackenzie And John Phillips source: allthatsinteresting.com

Mackenzie Phillips has become the unofficial spokeswoman for consensual incest after she famously admitted to having a years-long affair with her father, John Phillips of The Mamas and the Papas.

Phillips wrote of the relationship, which began when she was still a teenager, in her memoir and told of her father’s desire to elope with Mackenzie to Mexico where they could change identities and raise Mackenzie’s younger siblings as their own children.

Phillips’ younger sisters are torn on the issue, unsure of what to believe and upset that details of their family’s sordid history is up for public discussion. The situation reached an apex recently when sister Chyna Phillips was hospitalized for anxiety relating to the issue.

1 Allen And Patricia Muth source: rebelcircus.com

A brother-sister couple from Wisconsin, Allen and Patricia Muth met as adults and came to refer to each other as husband and wife. The couple had four children together one of whom was developmentally disabled.

When the Muths left the child in the care of a babysitter longer than they anticipated working months-long hitches as truckers, the child was reported as abandoned and the Muths’ union was brought to light.

Allen and Patricia eventually faced eight and five years of prison time respectively on charges of incest. The case drew parallels to the gay marriage debate.