In a plea agreement Fuentes and Wright both signed in federal court Tuesday, it said the "minors' prostitution services were advertised on backpage.com in order to solicit clients in Myrtle Beach."
Wright's mother, Tiffany Streeter, appeared shocked and saddened in court.
She told WSOC-TV's Blaine Tolison that her daughter may have helped Fuentes out of love, not to hurt children.
"I just feel like she wanted somebody to love her, that's all," Streeter said.
Fuentes set up the plan through a series of phone calls. Court documents said he called the girls in Myrtle Beach multiple times.
In one of his phone calls from jail, prosecutors said he bragged about the prostitution to a female friend, saying he had, "three little birdies going to the beach to do something for him."
At one point, documents say, "Wright expressed frustration that the minors were not working hard enough, had not made enough money, and were keeping money from her."
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Fuentes also reportedly talked to one of the girls about "being strong and making more money."
Prosecutors said Fuentes had a sexual relationship with one of the minors, but he denied the allegation. Attorneys on both sides said it wouldn't help his case anyway.
Sex trafficking of a minor carries a mandatory sentence of no less than 10 years in prison.
Fuentes' and Wright's sentencing date has not been set.