3 years or 4 years?

an ad on pearl channel to promote valentine's day:
a consultant: how long have you been married?
(simultaneously) the wife: 3 years the husband: 4 years
and then there is silence... the husband, to break the ice, points at the cheese on the table: oh... cheese... and picks one up and puts in his mouth
another silence, the husband sighs...

afterthought:
1. why is the husband so sure that he is the one who is wrong? why do we, the spectators, quickly assume that it's the husband who's wrong?
comments from a male friend: it doesn't matter whose answer is wrong, the fact that the husband is saying something different from his wife is wrong enough...

2. in fact, i can't remember who says 3 years and who says 4 years... assuming the husband answers a longer term than his wife, is he more wrong than saying a shorter term?
scenario a: wife- 3 years; husband- 4 years -> is he feeling 度日如年?
scenario b: wife- 4 years; husband- 3 years -> the husband can 'mend the wok' by saying 快樂不知時日過?
comments from a male friend: again, it doesn't matter whether the husband thought he got married longer or shorter than the fact or than what the wife thought, the fact that the husband is saying something different from his wife is wrong enough...

second thought... he may be right... no no no... he IS right... 辛苦了, 男士們!