Randy Daniella Hirst, 28 and Craig Smith, 31, were waiting for their stuffed crust pizza when they let their 'exuberant spirits get the better of them', a court heard.
An x-rated 18-minute clip shows Hirst performing a sex act on Smith up against the counter while several members of staff prepare food.
The footage, which was shown in court, first shows Hirst straddling a wet-floor sign before she is thrown in a sex position midair by Smith.
She then slides down Smith's trousers before appearing to perform oral sex, first standing and then crouching down on her knees.
Hirst then leans over the counter while Smith, wearing a white top and dark jeans, pulls down her knickers and thrusts several times from behind just feet away from workers.
The pair perform the sex act largely shielded away from the camera out of shot in the corner of the takeaway shop in Scarborough, North Yorks.
A court heard Hirst later described her behaviour as 'horrendous' and she 'cringed' when watching the CCTV footage back during police interview.
North Yorkshire Police were first made aware of the footage by the local media after it was posted on Twitter by a member of the Domino's staff.
Hirst pleaded guilty to committing 'an act outraging public decency by behaving in an indecent manner' after the frisky pizza shop incident.
Smith was found guilty in his absence, due to him being on remand for other offences.
The couple, from Bridlington, East Yorks, had spent the weekend drinking and celebrating Smith's birthday when they got the train to Scarborough on February 25 2016.
Prosecuting, Neil Holdsworth said: "This charge is committing an act outraging public decency by behaving in an indecent manner.
"This case is about an occasion where the two defendants engaged in sexual activity in a Domino's pizza outlet which was open to the public, with members of staff present."
Defending, Scott McLaughlin attempted to have the CCTV footage thrown out which was rejected by magistrates.
In mitigation, he said: "This case speaks for itself. Clearly, they were in drink and let their exuberant spirits get the better of them.
"There is nothing sinister in relation to the acts themselves, they are quite guarded.
"They have not been brazen in their actions.
"Miss Hirst's dirty laundry has been aired in public."
Magistrate Angela Beardshall said: "The prosecution has not obtained this footage illegally although it may well be it was distributed improperly.
"In coming to our decision we do take note Mr Smith has not attended but do deem him present via his solicitor.
"We have watched the footage and it's not disputed the male in the footage is Mr Smith.
"A great deal of the acts were lude, obscene and disgusting.
"Members of staff were present and the defendants could not be sure that members of the public would not enter the premises.
"We view this offence as so serious that it passes the custody threshold.
"The offence was in a public place. Members of the public were present and so were staff.
"Members of the public should not have to put up with this disgusting behaviour."
Both Hirst and Smith will be sentenced on October 17 at Scarborough Magistrates Court.