You may not be able to hide your lying eyes.

And your smile may be a thin disguise.

We thought that was just an Eagles song, bemoaning the perennially wounded heart of the 1970s poet-musician. But more than 30 years after "Lyin' Eyes" hit the airwaves, the Eagles are getting some backup from science.

Canadian researchers say there may be such a thing as a "cheating face."

Of course, it’s not so much the eyes or the smile — but the whole face that may give away infidelity, according to a study published in the journal Archives of Sexual Behavior.

By that, researchers mean the facial width-to-height ratio, or FWHR. To get that ratio, they measured the widest central area of the face against the height, which stretches from the top lip to the top of the eyelids.

Men who scored high in FWHR — in other words, men whose faces veered more towards the cinder-block end of the spectrum — were seen as having a higher sex drive and a propensity for it to spill over into infidelity.

The research is the marriage of two separate studies from Canadian universities. In the first one, 145 heterosexual students, both men and women, had their facial measurements taken. Then they were asked questions about their sex drive.

A similar study was conducted with 314 students from another university, but with added questions that probed the subjects’ attitudes toward infidelity.

Students with a high FWHR were found to be more interested in wandering outside the box of domestic fidelity. In other words, they tended to take the relationships bonds less seriously than their longer-faced counterparts.

So, there you have it. An easy swipe to the rejection pile on Tinder. Or not.

There’s also this longstanding idea of not judging someone by the way they look. Or, as Bruce Y. Lee writes in Forbes:

“Just what we need, another superficial way of judging people while dating. Using face dimensions to pick out cheaters can be a bit like saying, ‘please judge a book by its cover,’ or even, ‘please judge a book by the shape of its cover.’”

Sure, the research does suggest a correlation, but that hardly means wide-faced people are sex-frenzied philanders. After all, the study involved a relatively small and unique subject group — young people away from home, with hormones to burn.

It’s hard to draw concrete conclusions from those free radicals.

Which is why maybe we should wait a little longer before we judge those “lying” eyes.