It's a bodybuilding posing suit that is marketed as a thong, because the centre seam in the back is ruched and goes right up in there. The suit is fully lined with a soft silky material, including the centre seam in the back. It's very snug, comfortable, durable and well-made with double stitching on all seams. It sits higher on the hip bone than regular underwear or swimwear. I measured closely and it's true to size for the waist measurements. But I'm an average guy up front and I find the pouch is snug, so if you're a bigger guy, or you like more wiggle room, then size up. It's super sexy and I am impressed with the workmanship. Posing suits for pro bodybuilders go for double this price and not as well-made.