When the judge asked him what he did, a 60-year-old Madison man said, “I killed my wife, your honor.”  That happened at a Monday hearing for Steve D. Pirus.  He entered a guilty plea to charges he killed Lee Anne Pirus last year, then blew up their house.  Dane County Judge Nicholas McNamara sentenced the defendant to a term of life in prison.  Pirus admitted loosening a gas line to a dryer to cause the explosion.  A medical examiner found that his 50-year-old wife died from gunshot wounds, not the explosion.  Police found evidence Pirus had been talking with a woman in Russia that he planned to marry.