New Swear Word

My grandsons taught me,

and here it is: butt-crack hole.

May it please you daily.

The nine-year-old was sitting on the couch, reading

as his five-year-old brother stood on his head

beside him, his rear end near the elder’s face.

Their conversation turned to odors.

The rest, as they say, is anatomy, or philology.

I plan to use it figuratively, as in: Frank,

Why are you acting like a butt-crack hole?