DETROIT, United States (AFP) - Philanderers beware: spouses caught cheating in Michigan could end up spending the rest of their life in prison.

And not the emotional kind.

The state's appeals court recently ruled that extramarital flings can be prosecuted as first-degree criminal sexual conduct, a felony punishable by up to life in jail.

"We cannot help but question whether the Legislature actually intended the result we reach here today," Judge William Murphy wrote in a unanimous Court of Appeals panel, "but we are curtailed by the language of the statute from reaching any other conclusion."

"Technically," he added, "any time a person engages in sexual penetration in an adulterous relationship, he or she is guilty of CSC I," the most serious sexual assault charge in the state's criminal code.

Michigan still lists adultery as a felony, although no one has been convicted of the offense since 1971.

Nobody really expects prosecutors to go after cheating spouses. But the ruling has the local legal community twittering about its genuine intended target.

One theory floating around the courthouse is that the judges were taking a jab at the state Supreme Court, which has decreed that judges must interpret statutory language adopted by the Legislature literally, whatever the consequences.

Many other states allow judges to reject a literal interpretation if they believe it would lead to an absurd result.

Judge Murphy wrote that he encouraged "the Legislature to take a second look at the statutory language if they are troubled by our ruling."

A spokesman for the attoney general, who publicly admitted to adultery in November, declined to say whether they would press for legislative amendments to make it clear that only violent felonies involving an unwilling victim could trigger a first-degree CSC charge.

"This is so bizarre that it doesn't even merit a response," Rusty Hill said.

The appeals court decision involved a man convicted of trading prescription painkillers for sex.

In an attempt to increase his jail time, prosecutors used an obscure provision of the state's criminal law to charge him with criminal sexual conduct, which occurs whenever "sexual penetration occurs under circumstances involving the commission of any other felony."