KRIS JENNER so stressed out that running a simple errand nearly turned into a major disaster!

The reality TV mom tried to pick up a close pal’s 14-year-old son at a Los Angeles-area middle school, but she wasn’t on the boy’s parent-approved list. When a staffer questioned her, Kris blew a gasket, said a source at the scene.

“Kris tireid to play the fame car card, asking, ‘Don’t you know who I am?’ ” recalled the source.

“When the staffer said no, Kris whipped off her oversize sunglasses, and snapped, ‘Don’t you know who the Kardashians are?’

“The flummoxed staffer said, ‘I know the name, but it doesn’t mean much to me.’

“After that, Kris showed signs of becoming dangerously un­hinged, hurling expletives left and right at school employees.”

The irate dynamo then made several frantic calls to the child’s mother to get approval to take him home.

“After about a dozen calls, Kris finally reached her friend and got the go-ahead to leave school property with the boy,” said the source, adding that Kris continued to curse at staffers as she climbed into her Mercedes SUV with the kid and stormed off.

“Kris peeled out of the parking lot so fast that she narrowly avoided hitting a school bus, and kids had to scatter out of the way,” said the source.

“It could have been disas­trous! She needs to slow down and get a reality AND humility check.”