Robert Ferguson and Allison Ferguson are free on bond after being arrested last week. West Columbia police say the babysitter's mother filed the complaint July 12 after her daughter told her about the alleged incident.
According to police, the 15-year-old girl claimed the sex assault happened at the couple's apartment on July 7 when the Fergusons provided her alcohol and then both of them sexually assaulted her while she was under the influence of the alcohol.
Robert Ferguson, 23, is charged with sex assault of a child. Allison Ferguson, 26, is charged with indecency with a child.