WATERVILLE — Waterville Senior High School Principal Don Reiter will learn Monday night whether he will be fired or return to his job after hours of mostly private testimony at this week’s hearing. “There will be a decision Monday night,” said Sara Sylvester, chairman of the Waterville Board of Education. “We won’t be leaving without a decision.” The board is considering a recommendation from Superintendent Eric Haley that Reiter be dismissed for inappropriate conduct with a student based on an allegation that Reiter asked the student for sex. The board of seven women met in executive session Tuesday night for about four hours, and again Tuesday in a seven-hour long mostly private hearing that has brought criticism from those who attended as spectators. The board reviewed evidence and heard testimony from more than a dozen witnesses over two days and now is in the deliberation stage.