The other day, I saw this girl with her thong hanging out at a cafe. I wanted to tell her that the strap was showing but I didn't want to embarrass her in front of her friends.
That's when I thought about doing a deliberate thong flash so that she could take the hint. Unfortunately, her back was facing me, and there was no way for me to go in front of her and do a thong flash.
I might try this out on the street one day . Let's say there is a girl with a thong slip. Instead of telling her directly, I can just step into her peripheral vision and reveal my own thong by bending down.