An 18-year-old Grand Junction man has been arrested for allegedly having sex with a 13-year-old girl several times beginning in August of last year.
Nathan Koboski was arrested and booked into the Mesa County Jail on Wednesday.
According to the arrest affidavit, Koboski had sex with the minor three times while he was 17 and six times after he turned 18.
Records show that Koboski's sibling was friends with the victim and the sexual encounters occurred during sleepovers at the Koboski's apartment, located at 272 28 Road.
The arrest report doesn't show Koboski forcing the minor into sexual acts, but he did break up with the 13-year-old at the end of June because, according to the victim's statement, he said the age difference wasn't okay and it bothered him.
The victim also acknowledged that both of them thought they would get in trouble if they told anyone about the relationship.
The allegations came to light when the victim's father saw Facebook messages on his daughter's phone from Koboski on June 29.
One of the messages stated that the victim was fearful of being pregnant.
Several nude photos between Koboski and the victim were exchanged through Facebook Messenger as well, according to authorities.
Sheriff's officials say Koboski faces six counts of sexual assault on a child, six counts of sexual assault on a child with a pattern of abuse and 21 counts of internet sexual exploitation of a child.