I've been wearing white tights to the gym more often lately. Once I had a friend walk by and say "I like your yellow thong" Sometimes i make the thong completely visible and other times not as much. Before going to the gym i go through a series of changes between tights and my thong... which shows more or less. How brazen do i want to be. A pattern thong or just a solid color. I get a rush knowing my thong shows through. I have a pair of mesh knee length tights from Amazon brand Brave Person(fitting name) in white. I have yet to wear these. They are definitely see through. A friend has the gray pair and he also only wears thongs. I took a pic of his ass for him so he could see how nicely his red thong was showing through.
I have a pair of 2XU tights which sit lower on my waist. I'll usually wear a bright colored thong with those. If i bend over slightly the top of my thong will show. I don't think its a full whale tale type of exposure but for sure the color pops against the black.
I have many white short shorts where the thong will show as well. I've noticed that shorter workout shorts are becoming more popular at my gym. HALLELUJAH!
Now if only I would notice more guys in thongs.