United Airlines’ motto used to be “Fly the friendly skies,” but I’m pretty sure this is not what they had in mind.

Last week, a 25-year-old man was arrested for allegedly masturbating on a United flight from Spokane to Denver.

Kyle Pierce, of Florida, was busted after a teen-age girl sitting next to him spotted him working his joystick and alerted a flight attendant.

The teen was not the only witness. Another passenger was alerted by a friend who saw Pierce pleasuring himself.

“My friend turned to me and said, ‘That man is masturbating’ and in disbelief, I looked and saw his penis,” a woman told authorities. “I hit him in the arm with a book, which caused him to stop.”

I imagine it caused him to stop – especially if it was the arm in play. Talk about killing the magic of the moment – not to mention throwing off your rhythm.

I have to wonder what book she hit him with; it would be sweet irony if it was “Portnoy’s Complaint.” And speaking of sweet irony, the in-flight movie was “The Jerk.” (Honestly, I have no idea what the movie was; I just wanted to get that gag in).

In Pierce’s defense, plenty of people are scared of flying; that’s why they serve liquor on planes (well, that and also to distract you from the fact that you’re sitting in a space that would outlawed by the Geneva Convention if you were a prisoner of war). So, maybe someone suggested Pierce have a stiff one to calm his nerves and he misunderstood.

Another possible misunderstanding: Doctors sometimes prescribe small doses of Xanax to anxious flyers. Quoting from literature from Stanford University School of Medicine: “The alternative is to advise patients not to take medication, but encourage them to fly without it, instructing them in the principles of self-exposure.”

See? Plenty of room for misinterpretation. It could have happened to anyone.

If this case ever goes to trial, Pierce could cite the above as mitigating circumstances. I bet the evidence would stand up in court, and I think he has a good chance of getting himself off.

Pierce was taken into custody when his plane landed, and charged with obscene and indecent exposure. He faces penalties that include a $5,000 fine, 90 days in jail and, of course, premature blindness.