PIT Players Celebrate DeAngelo Williams' 'Birthday,' Fill Room with 700 Balloons

Thursday was not DeAngelo Williams' birthday.

But as a joke about him being "so old," the 33-year-old running back's Pittsburgh Steelers teammates celebrated. A day later, they sang to him while stretching and appeared to spray him with Silly String.

The real prank was filling his room with what kicker Chris Boswell described as 700 balloons:

Williams wasn't thrilled, but seemed to be a good sport, per ESPN.com's Jeremy Fowler:

"

"I don't think it's funny, but everybody else thinks it's funny,” Williams said with a laugh. "What's the worst is somebody comes up and has no idea and is like, 'Hey man, happy birthday,' and I'm like, 'It's not my birthday,' and they are like, 'Well, why did somebody say happy birthday to you?'"

"

This has become a running joke in Pittsburgh:

"

Players got the fans to sing Happy Birthday to Deangelo Willaims today (who was born April 25) #SteelersCamp #SVC pic.twitter.com/eVhlfg275l

— St. Vincent College (@MySaintVincent) July 31, 2016"

Here's another look at the Steelers' most recent prank:

Williams' birthday is April 25.

[h/t For The Win]