Why, you may ask?
Well, we could talk about keeping the skin soft and smooth in those "delicate" areas. Or, how it gives the appearance that no other eyes get to see everthing. But the real reason is:
At my age, I need all the guideance I can get of where to go and where to find the areas of play. Especialy in the dark. Those tan lines are like gidelines for us old guys

Anyone else like tan lines?