Mystery of sad Detroit Lions fan on downtown billboard solved: PHOTO

It must be difficult being a Detroit Lions fan for the past half century or so and kind of mean when someone uses your face on a giant billboard to publicly ridicule that diehard loyalty — but it's downright funny when that someone with the warped sense of humor is your own dad.

As it turns out, the giant billboard featuring the downtrodden Lions fan that popped up in downtown Detroit last month was the work of the poor guy's own father.

Steve Vlahakis purchased the enormous billboard so he could put a larger-than-life picture of his son, 23-year-old Niko Vlahakis, on view — just a couple blocks from Niko's work.

Niko first found out about it from a friend in Arizona who saw a photo of the billboard — featuring the downcast face of himself decked out in Lions gear — on Twitter.

This sad @DetroitLionsNFL billboard appeared downtown recently. Says a lot. pic.twitter.com/GVH55NqLPQ
— Rory Carroll (@Rory_Carroll) January 28, 2014

"When I first saw it, I was shocked. After a long day at work and getting a beer, I turned the corner and was speechless," he told The Huffington Post. "I definitely needed another beer after that. ...Every day when I come to work I have to see myself."

He initially had no idea who put up the billboard. When he eventually called his dad, the elder Vlahakis burst out laughing.

The father said he and some friends leased the billboard space from CBS Outdoors and it was not sponsored by the NFL team.

Niko's image — which became a popular meme — was captured by ESPN during the Dec. 16 game against the Ravens before Justin Tucker kicked a 61-yard field goal to defeat the Lions 18-16 in the final minute. 

"I had a great time until (Matt) Stafford threw an interception in the third," said the younger Vlahakis, who attended the game as a last-minute surprise from his father. "Once he threw that interception, I'm just sitting there a sad Lions fan, shaking my head. No words could explain it. You can see it on my face."

That face will be upon the billboard through the end of February.