I'm wearing string underwear for the first time and I'm worried about tan lines. All the bikinis I've worn mostly covered the butt, so I've got visible tan lines when I'm wearing slightly smaller underwear. Is this unattractive? And girls, do you think it looks weird?
Tan lines are attractive? Well, you learn something new every day.
This makes me wonder who is going to see your string underwear that will not see you naked? They will see your tan lines when you are naked, so really what is the difference with seeing them in underwear? No big deal, though.