My son is on probation for another 9 months, because of an ex girlfriend filing charges on him. He has been seeing a girl, age 20, heis is also 20, and she says she loves him very much and wants to move in with him. They are palanning to get married in a year and half. Does he have to ask permission from his PO to get engaged and for her to move in?

To get engaged no, for her to move in, only if his probation restricts who he can live with.