This upload contains a swimsuit for your Sims gents from the Edwardian era. Six colors, custom edited mesh with bump maps and Maxis match as usual. Found in TSR Category 'Sims 4 Male Swimwear'

https://www.thesimsresource.com/members/Lollaleeloo/downloads/details/category/sims4-clothing-male-teenadultelder-swimwear/title/vintage-swimming-suit-by-lollaleeloo/id/1315961/