Swimming Trunks with belts incorporated into them have always hit my button. It's one of those incongruous combinations that makes the mind grope for an explanation. In the days before lycra and water repellent fabrics they actually served a purpose - preventing wet cotton and flannel trunks from sagging under the weight of water to an immodest degree. With modern fabrics the ubiquitous drawstring is man enough to fulfil the same role, but belts provide a showy fashion alternative.
No ID on the model yet, info welcome