POTTAWATOMIE COUNTY, Okla. -- This summer, a Pottawatomie County, Okla., man will learn his punishment after investigators say he killed his stepfather in 2013 by giving him a wedgie, KOCO-TV reports Brad Davis pleaded guilty to first-degree manslaughter in the death of Denver St. Clair.An autopsy found that St. Clair died after an elastic band on his underwear was pulled over his head, cutting off his air.Prosecutors are pushing for a 35-year prison sentence. ABC News reported in 2014 that Davis, a former Marine, told police St. Clair had spoken "ill of Davis' mother," and then threw the first punch. The men had been drinking, investigators told ABC affiliate KNXV Davis said he fought back and then gave his father an "atomic wedgie." The move is most often used as a prank among children and teenagers.