have some explaining to do

チリの鉱山落盤事故で，鉱山夫の本妻が愛人とはちあわせしてちょっとした騒ぎになっています。have some explaining to doという表現は見慣れない形ですが，「苦しい説明をする」感じがします。小山本くん，そんな経験はありませんか？（UG）
Wife runs into mistress at mine
One of the trapped Chilean miners is going to have some explaining to do after his wife ran into his mistress at the mine's entrance.
Britain's Sun newspaper reports the wife of Yonni Barrios, Marta Salinas, was stunned and upset to find his girlfriend Susana Valenzuela also conducting a vigil for him.
Salinas told the newspaper: "Barrios is my husband. He loves me and I am his devoted wife. This woman has no legitimacy."
http://www.watoday.com.au/world/wife-runs-into-mistress-at-mine-20100903-14rxt.html