COLUMBUS: A University of Michigan football fan loves his girlfriend so much that he proposed to her on hostile territory: the playing field of her favorites, the archrival Ohio State Buckeyes.Abbey Zellers didn’t know what was happening Tuesday evening when Johnny Wakefield led her to the empty Ohio Stadium, then down to the 50-yard line. The Columbus Dispatch reported that she told him, “We’ve got to get out of here. Someone is going to kick us out.”That’s when Wakefield dropped to one knee and popped the question. He had paid $150 to use the stadium for an hour, for the purpose of the proposal.Zellers, 28, said yes right away. “It was a total shock,” she said, adding that she thought they were merely celebrating their 10-month anniversary.She grew up in Wadsworth following Ohio State and now lives in central Ohio, as does Wakefield, 27. His admiration for the Michigan Wolverines is a holdover from his parents, both Detroit natives.Ohio State receives about five stadium “rental” requests for marriage proposals each year and puts the money in the athletic department’s general funds, said Brittan Roth, the department’s assistant director of event management.Zellers got another surprise later Tuesday when she was taken to an engagement party. Her younger sister, Keli-Jo White, was on hand even though she was supposed to be retaking part of a test at the Medical University of South Carolina.Her professor, an Ohio State graduate, agreed to reschedule as long as she could see a photo of the proposal — showing “Michigan” bowing down in Ohio Stadium.