The father of missing teen Sebastian Rogers has ordered a private investigator to stop looking for his son more than three months after he mysteriously vanished from his bedroom. Sebastian, a 15-year-old with autism, was last seen the night of Feb. 25, at the Hendersonville, Tennessee, home he shared with his mother, Katie Proudfoot, and his stepfather, Chris Proudfoot, authorities said. In April, Sebastian’s biological dad, Seth Rogers, hired two private investigators to look into the case after local authorities couldn’t locate his son. Rogers is now demanding a PI stop searching for the tee…