Warning: This article discusses an incestual relationship.
A mother and son in the US are blaming their intimate relationship on what they claim is a rare genetic sexual attraction (GSA) disorder.
GSA is a phenomenon when sexual feelings develop between two family members who first meet as adults.
Michigan man Ben Ford was adopted at birth and reunited with his biological mother in 2013 after he wrote a letter to her to get in touch.
Kim West admitted she had sex dreams about her son after he reached out, according to The Mirror.
The incestual couple said they had an "instant bond" and blamed their relationship on GSA.
The term originated in the US in the 1980s after Barbara Gonyo had an intimate relationship with her son, who she met 26 years after she put him up for adoption and founded a support group.
Some experts have dismissed GSA as pseudoscience, but psychologist Corinne Sweet has come across it as a therapist.
"At a genetic level we are conditioned to find people who look like us attractive, in the first few seconds of meeting someone, we make a judgement about whether they are friend or foe, and whether they can help us reproduce our genes," Sweet told The New Day.
Sweet also told The New Day that West could have "enveloped her son sexually" to potentially protect herself from her son's rage and sense of betrayal.
As reported by The Sun, Ford said: "When I met Kim, I couldn't think of her as my mum but instead as a sexual being."
Ford left his wife Victoria for his mother and told his wife he couldn't perform sexually with her anymore.
"Every time I have had sex with you since I met her, I imagine it's her I am kissing - otherwise I can't perform."
The couple went into hiding after the relationship was made public due to incest being illegal in Michigan, The Mirror reported.
If caught, Ford and West could face up to 15 years in prison and be put on the sex register for life.