A husband went on a day trip to France - forgetting he had left his mother-in-law waiting in the ferry car park at Dover.The man and his wife dropped their vehicle off in a long stay car park in Dover, after driving 300 miles from Bootle in Merseyside, reports Metro.But the couple - who were treating their relative to a cross-channel day trip - then forgot all about her and left her in the back of the car.It was only when police at the Port of Dover received an 'unusual' phone call from the absent-minded couple as they docked in France that they were able to find the pensioner."Officers located the vehicle and ensured the safety and welfare of the elderly lady until her grown up children returned several hours later," a force spokesman said."They told us they had forgotten that their elderly mother was still in their car they had parked in the multistorey car park before their day trip."The embarrassed couple caught the next ferry back to Britain to pick up the abandoned woman who was in her 70s."The trip was meant to be a treat, but it turned into a nightmare for the poor old dear, who was left sitting in the back seat of the car wondering what was going on," a police source said."She must have been there for at least six hours, but she didn't cause a fuss - she just stayed where she was and waited for them to return - and then she gave them hell." Source: orange news