A McDonald’s dessert run last night has proven costly for a grandmother who was caught five times over the legal alcohol limit.

Dandenong Highway Patrol had pulled over on the Princes Highway at about 7.30pm on Monday when a young woman arrived and told them a female driver had crashed into her vehicle nearby and she was concerned the woman shouldn’t be driving.

While police were getting further details from the woman, a two-car collision happened as they watched on.

The young woman told police one of the vehicles involved was the same car that had crashed into her.

The 60-year-old woman behind the wheel returned an alleged breath test reading of .249.

The Noble Park woman told police she was driving to McDonald’s to buy a sundae for her grandson.

Her license has been suspended for 12 months and she will be charged on summons with drink driving and traffic offences.

The woman’s car has also been impounded for 30 days.