Youth female swimmers like cheeky one piece swimsuit. They pull the swimsuit up into their buns, turning them into one piece thong. ALL the major brands offer ultra cheeky one piece swimsuit in their collection, because it is what youth female swimmers want. Some brands and some models : ARENA : team https://www.arenasport.com/fr_fr/004763-maillot-de-bain-femme-team-dos-swim-tech-uni.html#280=54859 Their "team" one piece is a classic. Most of the girls start the "cheeky side" by this one, before trying cheekier brands. JOLYN : lexi https://jolyn.com/products/swim-onesie-lexi?variant=42434518810797 they now offer the "lexi" swimsuit. No difference with a OPT. Unluckily, it is sold only in USA and canada. I hope I could buy it for my wife in europe soon (I use a VPN to acceed to the US jolyn website, but can't buy it). TURBO : sirene https://turboswim.com/en/women/swimsuits-sirene/ Their "sirene" model is very cheeky. It turns quickly into a thong while swimming. At a reasonnable price, I see more and more gals with this model. SPEEDO : They have 2 models. One with a ultra cheeky back (barely bum coverage). https://us.speedo.com/printed-fixed-back-one-piece/13234729.html I have never seen one at the pool. A second one, with very high leg cut and cheeky back coverage. Lot of colors. I have seen it several times this year, with lot of variants. https://us.speedo.com/printed-double-lace-back-one-piece/14010395.html Gals have a lot of choice. At the same time, men have very few choices.

Try swimhxby. Have quite a few of them for myself. Racer back, hydrasuit, both in thong and full back. Great sizing and wonderful fabric.

for men have a look at these https://www.ml-sport24.de/epages/61229127.sf/de_DE/?ObjectPath=/Shops/61229127/Categories/Herren/Stringbodys

This story is about a swimsuit I didn't even see! Was at Haulover Beach on a somewhat breezy day and seas were about 4 ft. The lifeguards had red flags up and virtually no one was in the water. I'd noticed this 30's fit nude couple about 15 yards away. He had a faint trunks tanline. She had a faint thong tanline on her ass and a strange multistrap crossed tanline on her upper back. After a while I look over and she's tucking her long hair up into a swim cap. She strides down into the surf and dives in! She turns South and starts swimming out and along the shore- maybe 30-40 yards off shore beyond the breaking waves. She swims a crawl efficiently- obviously an experienced open water swimmer! That explained the OPT tanline with the straps across the back to hold her top up while swimming- like a competition suit- butt apparently had a thong bottom. So she swims out of sight off shore the textile section of the beach while swimming a nude crawl! She didn't return for almost an hour swimming back to her spot. Her man didn't seem to pay any attention to where she was- obviously does this a lot. That's badass! Swimming nude offshore the textile beach while burning off a thong tanline!

I have seen quite a few cheeky one piece swimsuits lately. I don't know if they are designed that way on purpose, but it makes total sense. Swimsuits tend to ride up as you're swimming, so a cheeky cut just works with the body's natural movement.

Jolyn offers some thong style one pieces and some very cheekie one pieces. I have ordered from them multiple times. I have this suit in two different colors and it can very easily be worn as a thong with how cheekie it is. And it provides enough coverage in the front for men. https://jolyn.com/products/swim-onesies-catherine?variant=43936411844781