His milkshake brought the gross-out to the yard.

A DoorDash delivery driver was caught on a doorbell camera sucking up the sweet treat he’s about to deliver to unsuspecting Rishab Malhotra’s home in Stockton, Calif.

Rishab, 14, says he enjoyed that cookies and cream milkshake — until the next day when he found out he wasn’t the only one who took pleasure in his Cold Stone Creamery order.

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“My dad told me to check out the video from last night — and once I checked it out I [watched] five, six times,” the teen tells Fox 40. “I felt really disgusted about what had happened.”

Yes, the family didn’t discover the dirty deed until it was too late.

“I looked at it, [and thought], ‘Hey, the guy who delivered the food was sipping out of my son’s Cold Stone,'” says dad and homeowner Rajesh Malhotra. “I was like, ‘Whoa, that’s crazy.’ I mean, how can someone jeopardize the product like that, especially the food?”

The Malhotras say they’re glad no one got sick from the incident — but the experience definitely left them with a bad taste in their mouths when it comes to food delivery services.

“We have trust between the company and the drivers,” Rajesh says. “Once that trust is broken, we can’t go back to them.”

They expect an apology from DoorDash.

“They just need proper training, Rajesh says. “… Hey, what you did was wrong — and we want to make sure that he doesn’t do that to other people.”

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The homeowner told FOX40 he reported the incident to the company the next day and provided a copy of the video. That was more than two weeks ago.

This story originally appeared in The New York Post.