IDA GROVE — A substitute teacher has been accused of having sexual relationships with students at two northwest Iowa high schools. Court records show 32-year-old John Tietsort, of rural Battle Creek, is charged in Ida County with two counts of sexual exploitation by a school employee and three counts of lascivious conduct with a minor. The Iowa Department of Public Safety says in a news release that while working as a substitute teacher, Tietsort had repeated sexual contact with the two high school students.