HOW TO SPOT ONE: Are you in a British park? Is the temperature in excess of 15°C? Then simply gaze around you a moment aaand… there. There he is – nipples out, pecs rippling, abs glazed with protein-shake-laced sweat.

Nipples out, pecs rippling, abs glazed with protein-shake-laced sweat

You’ll probably observe the Topless Bro take a break from running to perform some (admittedly impressive) feats of strength: chin-ups on the swings, clapping press-ups by the duck pond. But then he leaps back to his feet, subtly employs his peripheral vision to double-check that the entire park is gazing wistfully at him (which they are, despite themselves), and gallops off again, high-fiveing himself in his mind.

HOW TO DRIVE THEM MENTAL: Ask him if he even lifts, bro.