They thought it was a real Shake-down.

Just in case guilt tipping wasn’t already running amok. An incensed customer has accused Shake Shack of raising the prices on their order after they didn’t leave a gratuity at the self-checkout kiosk.

“My wife says that if you don’t tip at Shake Shack, they make it more expensive per item,” declared TikTok creator B.D. Powell in a video with 4.2 million views.

TikTokker B.D. Powell claimed that Shake Shack raised prices on their milkshake order after they selected the “no tip” option at the self-checkout kiosk. Emmy Park for NY Post The kiosk’s disclaimer after Powell selected the “no tip” option. Reddit/r/mildlyinfuriating

He decided to test this theory by ordering three classic shakes — a vanilla, cookies & cream and strawberry — at a branch at an airport in Salt Lake City.

The Post reached out to Shake Shack for comment.

They cost $5.99 each according to the order screen.

The automated check-out then took them to the tip screen, where they were offered 15%, 18%, and 20% gratuity options as well as the choice to leave “no tip.”

The milkshakes were 50 cents more expensive after Powell selected the “no tip” option. Reddit/r/mildlyinfuriating

But when Powell selected the latter — as is common at self-service outlets — all hell broke loose.

The screen displayed the message, “Uh Oh! There has been a pricing update on one or more of your cart items. Please review these changes in your cart.”

Upon obliging, the three shakes now showed prices of $6.49 each — total price increase of $1.50.

“Everything just went up fifty cents,” lamented Powell, who warned viewers to “not go” to Shake Shack.

Shake Shack has denied the allegations. Tada Images – stock.adobe.com

“Tipping culture in the US has reached an intolerable toxic limit,” said a third.

However, others claimed that the customer had failed to establish a causal link with one Redditor noting, “you didn’t show what happens to the pricing when you do leave a tip.”

Meanwhile others accused Powell of skullduggery, claiming that he’d made a normal time-based price change look like a no-tip penalty.

“Pretty sure I saw this in a different sub, and people were saying the price increased because shake shack has a late night convenience fee past a certain time, and the people videoing timed the price change to make it look like a tip issue,” theorized one viewer.

Shake Shack has since denied that they were scam-burgering patrons.

“Thank you for bringing this to our attention,” they wrote in the TikTok comments, which have since been disabled. “This is not a Shake Shack policy, and we’re currently looking into it with our licensee, HMSHost, that operates the Salt Lake City airport location and kiosk system.”