"Man flu" and sexism

I'm genuinely happy that TV ads which are sexist against women aren't allowed any more. But it still seems ok to do ads which are sexist against men. Take for example a recent Boots ad, which presents a man as malingering in bed with a cold, and his wife with the same cold carrying on doing shopping and looking after children. This seems to be presented as a typical situation.

I am aware of the myth of "man flu", but I have never come across a single case. When I worked as a teacher, women were (it seemed to me) slightly more likely to be absent with illness than men. However, I suspect that was because the few departments where people shouldn't carry on working if they had a slight cold (e.g. food technology) were mostly staffed by women, and the departments where there were more men (e.g. chemistry) were departments where teachers could carry on working with a cold.

I find it odd that adverts which are sexist and demeaning to women are (rightly) banned, but adverts which seem sexist and demeaning to men, and particularly to the role of father, are allowed...