Kris Humphries -- Wedding Ring DISASTER Averted

Kim Kardashian's husband just avoided every married man's nightmare -- the ole, "Where the [bleep] is your ring?" convo -- when his $10,000 wedding band went missing ... temporarily.

Kris Humphries can thank a fellow traveler (above) for finding his ring at a TSA checkpoint in Minneapolis-St. Paul Airport on Friday.

Sources close to Kris tell us the drama started when he had to take off his Lorraine Schwartz designed ring to go through the metal detector. We're told Kris accidentally dropped the ring while putting it back on -- but luckily the guy behind Kris recognized him as "Kim's husband."

The good samaritan -- and "Keeping up With the Kardashians" fan -- tells TMZ he got down on his hands and knees, searched for the ring, found it ... and returned it to Kris.