But the Liverpool Echo reports the victim mouthed "help" three times to the McDonald's employee at the drive-thru window and police were called.
Prior, aged 40, was jailed today for 18 months and handed a five-year Criminal Behaviour Order with restrictions including a ban on him working as or pretending to be a taxi driver.
As Prior was sent down, his brother said "wrong that you know, on every f***ing level", then screamed as he left Liverpool Crown Court.
Sentencing the thug, Judge Rachel Smith said Prior "misled" the woman and "touched her inappropriately".
"Members of the public have the right to be safe from harm when they choose to use a taxi," she added.