A 21-year-old woman who allegedly competed with her half-sister as to who could engage in sexual intercourse with their father first was charged with incest. After police received a tip about the sexual relationship between Samantha Kershner and her father Travis Fieldgrove, 39, both were arrested at their Hastings, Nebraska, residence last week, the Daily Mail reported.

According to police, Kershner and Fieldgrove knew they were biologically related. Nonetheless, both admitted to having a romantic and sexual relationship despite the same. When Kershner was 17, she told her mother she wanted to know who her biological father was. It was only then they met for the first time.

For three years, Kershner and Fieldgrove maintained a father-daughter relationship. Authorities said the duo had sex for the first time in September last year, although it is unclear how their relationship turned sexual in nature.

Kershner told police she apparently was in "jealous competition" with her half-sister about who could get into bed with Fieldgrove first. In September, her mother notified police about their unconventional relationship. When Fieldgrove learned they were being investigated for incest, he married his daughter the following month at the Adams County Courthouse.

Both parties intending to marry were needed to provide full names of their biological parents for approval, per marriage licensing requirements at the courthouse. It was found Kershner's birth certificate did not list Fieldgrove as her father.

Fieldgrove then told police he didn't believe Kershner was his daughter considering his name wasn't listed on the certificate. However, a paternity test later showed there was a 99.999 percent chance he was her biological father. 

The duo was subsequently charged with one count of incest each and is now being held at Hall County Jail. Fieldgrove's bond was set at $100,000, while Kershner's was finalized at $20,000. If convicted, they each face eight years behind bars.