Colin Charles Dewe admitted in the Gore District Court today of wilfully doing an indecent act within view of a public place, namely McDonald's.
The summary of facts, which were not read out in court, said the act happened about 7.49pm on October 27 last year.
After they had ordered food, Dewe, who was the driver of the car, received a sexual act.
''The act was performed in clear view of the victim who served the food,'' the summary said.
Judge Russell Walker said Dewe had every right to feel embarrassed.
''Your behaviour on this night was utterly inappropriate.''
He was ordered to pay $250 emotional harm reparation to the victim.