By Robbie Owens

DALLAS (CBSDFW.COM) – It was the biggest birthday bash in town– and probably the coolest

7-Eleven, on this eleventh day of the seventh month, celebrated the chain’s 91st birthday with its annual Free Slurpee Day.

“Yummy!” exclaims 13-year-old Maya Nitz while enjoying a free Coca-Cola Slurpee at a North Dallas location. She says she was able to talk her dad into driving her to the store, because “he wanted one, too.”

But, leave it to a couple of college friends to turn 7-Eleven’s Free Slurpee day, into a fun-filled marathon.

“Our goal is 50 7-Elevens,” explained Regan Clifton with an infectious laugh. “This is number 17.”

free 7-Eleven Slurpee (CBS11)

Pal Emily Smith picks up the story from there. “We started doing it a few years ago just for fun, so we could have like, three or four and then it just turned into an every year try to beat our record.”

“It is so much fun,” explains Smith, and then adding “we both took of work today for this!”

Smith is a law student at the University of Oklahoma. Clifton attends the University of Houston.

“We’re best friends and we don’t go to the same college,” explained Clifton, “so when I come home it’s a great way to spend time with each other. We have this huge adventure all day.”

The friends tell me that they put Free Slurpee Day on the calendar, and is a command appearance.

“She didn’t come home for Mother’s Day, but she did come home for this,” added Smith with a laugh.

I threatened to tell. But, hopefully all will be forgiven. They plan to share.

“We have a cooler set up in the car with some Tupperware and we’ve been pouring them in there and taking them home after this,” said Smith. “Mostly why we do it, is for the fun. When we get home, they’re all melted, really not enough to go around. We do it for the fun.”

The chain was expected to give away 9,000,000 free Slurpees on Wednesday. The promotion ended at 7:00 p.m.