Dear Mary: How can I tell a man at yoga class to cover up?

Q. My sister runs a yoga school and a middle-aged gentleman has joined. Although she is delighted to encourage male membership in a very female-dominated session, his male membership tends to make appearances throughout the lesson due to the looseness of the shorts he wears. In her position at the
front teaching, my sister is the only one exposed to these displays and there is little hard evidence that this is anything other than a gentleman enjoying the free-flowing nature of the class. However it can put her off. How would you cover this?
— W.C., address withheld

A. Benign (i.e. incognisant) flashing is a recurrent theme in Dear Mary’s mailbag. It is most widespread among male pyjama-wearers within house parties. Once someone tips off the offender, he is usually mortified and takes care not to become a repeat offender. Since buttoned pyjama flies are a rarity, the only solution is to get properly dressed.