the study of 1,302 german found women who did not work did an average of 6.8 hours before their husband 's retired .
but they are still lagging behind their stay-at-home female partners when it comes to sharing the burden .
division of labour : men do just two hours of housework a day while working , which increases to 3.9 after they retired .
but it is still far less than the amount carried out by their stay-at-home wives that