White CX

[n2er]

[tightjeans]

Guys that suit is in no way a "swim suit" by any definition I know of. For sunning OK, the fellow wearing it can pull it off but it is beyond a "swim suit".

[Torchwatch]

There is a tradition of white transparent swim suits and also a tradition of well extreme pouch swim suits. this swim bikini fits into both categories and is shown being used for swimming. It therefore fits the definition of a swim suit.
Whether it fits in with your consideration of good taste or public decency is another question but for a young guy alone or among friends on a quiet beach it does seem fun.
The trouble with youth is that it is fleeting and we don't realise what we have, this young man is simply enjoying his youth and making the rest of us jealous.