[sebbie]

Really skimpy thong underwear/swimsuits are readily available from eBay and Amazon among others. The ones I have are under the IKINGSKY brand and are basically just a pouch along with a narrow elastic band for the waistband and another for the back. The back crawls snuggly between the glutes. These are small enough and skimpy enough that I could use one of them as an underliner for a larger swim brief such as a Speedo.

I have a Speedo Solar in the classic Royal blue color. I have an IKINGSKY thong in a bright orange. Why not use the IKINGSKY thong as an underliner for the Speedo Solar. The back of the IKINSKY will crawl up my butt with every step and give me a fun "kick" that the Solar is unable to do. Interestingly, the "T" in the back shows above the waist band of the bright blue Solar but in bright orange. I'm fully covered in the rear as the IKINGSKY covers the crease. Yet something more than Just a Solar is revealed, with the two bright contrasting colors.

Most thongs are probably too big to make an effective liner but the IKINSKY is perfect for this task. And the IKINSKY pouch holds the penis in the perfect "up" position under the Speedo Solar.