Dear Mary: how do I set up two young people?

Q. I have invited some younger friends to stay with me at a family house in Spain. Among the party will be an excellent young fellow who I sense is attracted to my niece, who will also be joining us for a few days. Were I to ask if she is interested, she would think such a question ‘gross’ – but she should be, because he is an all-round star. Like so many of his age, though, he has a somewhat dithering and unconfident manner. Given that it will be too hot to dance, any thoughts about how I can help things move forward between them? They are both single.

– Name and address withheld

A. At an opportune moment, having engineered a chat, sit the pair down on a sofa and hand them your mobile preloaded with a relevant short podcast on the topic you have been discussing. Produce old-style tethered earphones for them to share, with one end in each ear, so they have to sit close to one another. The enforced proximity will clarify any latent reciprocal chemistry and facilitate a private overture for fuller intimacy.

Q. I was sitting opposite a young woman and her mother on a train and it was clear that the girl had impetigo but that neither party realised she had this infectious complaint, as they were describing it as ‘sun blisters’. I didn’t know how, without seeming patronising or grand (I can’t help my voice), to tell them she had this condition associated with poor hygiene. How could I have warned her, Mary?