What does mean "out of the sack" in the following sentence?
"To watch Johnny Depp's titular voluptuary in "The Libertine" take a mincing step around a dead rat whisker-deep in mud is to appreciate that the life of a 17th-century hedonist was rough going, at least out of the sack. "
"To watch Johnny Depp's titular voluptuary in "The Libertine" take a mincing step around a dead rat whisker-deep in mud is to appreciate that the life of a 17th-century hedonist was rough going, at least out of the sack. "