Mary works in art, so she points at the works we encounter and gives additional information. We’re at London’s Frieze sculpture exhibition and she’s kind enough to give her explanations as if she’s telling the kids, while knowing full well that I’m listening in equal ignorance. Unfortunately, she wasn’t available earlier today, when my son asked what a sculpture actually was. I didn’t want to get into the difference between objects in two versus three dimensions, so I settled on saying that a sculpture is like a model, not a drawing, and it can be of a person, an animal, or a thing, but it might also just be a shape, or a feeling. I was pleased with this, but the boy seemed unsatisfied, so I loaded up the Frieze website to show him some sculptures on my phone. When he started picking out the ones he wanted me to buy, he was confused, but greatly impressed, when I explained they are probably too expensive for us. We met Mary, Neave and their two boys, Manu and Rohan, feeling very smug about the day ahead. One of the best things about being Irish in London is you get a sort of cultural free pass to enjoy such pursuits without turning yourself into a pretzel of self-loathing. A decade here has taught me that upper middle-class English people long ago decided not to interrogate the advantages gifted to them and so they do all they can to change the subject to cultural signifiers of said privilege. In practice, this means they get to keep all their money, but have to affect wry abashment at the fact they patronise the National Trust, or spend pleasant Sundays showing very expensive sculptures to their four-year-olds. In this one respect, at least, Irish people are exempt from such class theatre, so we rejoice in the fact that public art is a public good and the loveliness of seeing three boys frolicking in the park and reacting to the works in exactly the way anyone should: wonder, boredom, amusement, outrage. There are signs saying DO NOT TOUCH, but they are secondary to the silent invitation so many of them issue to three curious boys who quickly set about touching every object they see. We scolded and chided, before security guards assured us it was OK, in that mildly injurious way that suggests it might be OK just this once. My son’s favourite was George Rickey’s Five Lines In Parallel Planes, a kinetic sculpture with tongs that swing in the breeze, and Speaker’s Corner by Pablo Reinoso, a suite of cast-metal deck chairs whose backs extend into a tangle of wriggling, squirming planks, 20ft in the air. It is the latter the boy recalls when he gets home and begins constructing a high-backed chair of his own from Lego. ‘That’s wonderful,’ I say, moved by his being so inspired. ‘Want to buy it?’ he asks. My heart swells with pride that he’s figured art out so quickly.