Mystery solved.

If you recall, I was a little curious to know what and if, anything is worn under the lungis!! While walking around I did see a few tourists trying to wear these pieces of clothing and I think the lovely brown legs sticking out is a little more pleasing to the eye than white legs which never see the sun. I guess we can get used to anything and it is a huge laundry saver. Also, I am told, very convenient for men!
A "funny' thing happened one day while we were sitting on our balcony overlooking the backwaters. A houseboat was returning with a party of Indian men. They were laughing and singing  and clapping and it appeared that they had had a festive time.
Next to the driver a young fellow was perched on the edge with his back to us. The next thing he toppled over backwards into the water. As you can imagine, panic struck. We even wanted to jump in and save the fellow.

Taken from our balcony.

The quick thinking driver pulled on the brake, the assistant through the anchor overboard and pulled off his lungi and dived in! a second hero jumped in but by then the victim had his head out of the water and was pulling on the ropes which were hanging over the side of the boat.

There was much cheering and laughing that followed and we raised our glasses to the successful operation.....and for me the mystery was solved. YES the men do wear underwear, unlike most "true scotsmen".