Why All American Super Heroes wear underwear over pants?

In the beginning all Americans Super hero’s used to wear underwear underneath the pants. However despite they didn't look so bad, the disgusting feeling of nudity always used to haunt them. They used to be part of the secret societies of super hero’s known as Super Judgment league.
That day was chosen for the most critical decision of their lives. It was almost midnight when suddenly superman flew away only wearing his blue pant but forgot his red underwear. When he recalled that, he was in the middle of the battle and he was about to save the world. At this point, he simply could not go back and wear his underwear and the damage suddenly was done. After he won the war, he suddenly called all the super heroes, including Spiderman, Batman, X-Men etc for that urgent meeting.
Though everybody was busy in keeping the society of US terror free, the agenda was so urgent that they procrastinated everything and joined the conclave.
Super Man stared everybody with the question of his life time. This was the second thing in his whole life that scared him the most, after Krypton. When he started to spill the beans of his fear, there was the pin drop silence of in the room. When Super Man asked each and every one, if the same has ever happened with them as well. All the super heroes find that question too personal and embarrassing. What scared Super Man more was when Cat Woman asked him if she can consult her lawyer before answering the question. When they took the sacred oath of not disclosing the answers outside the conclave and all the answers will be buried as soon as they will take the shape, Bat Man culled all the possible power within and admitted that one day, when he was suddenly called by the Joker one night, his whole attire was intact minus underwear, and he took his bat car to reach the destination. Whole time his mind was preoccupied by the fear of not wearing the underwear that Joker was almost defeated him. Suddenly Robin shared his spared underwear and he used his ability to hide to wear that and he won. What displayed to his fans was after all something else and all secrets are actually hide’s reality.
Tears start to fall from all super heroes eyes when Bat Man finished his engrossing story. Spider Man didn't disclose the whole incidence however admitted he too had forgotten his underwear at the several occasions. However everybody was remained in awe when Sabertooth admitted that he was not wearing underwear at that very moment of conclave as the meeting was called in the hurry and he had his habit of sleeping wearing nothing.
"Now this thing has to come to an end or else our survival will be biggest question mark" Superman uttered these words with so much emotion that his hand was shivering.
"What do you all suggest???" Batman asked everyone in the room.
There was sound of whispers and voices of sobbing.
After 1 hour of struggle and when chaos started to happen in outside world where all the possible survived villain came out of hibernation, Fantastic Four suggested "Though we know it will look silly but only way we can confirm that we are wearing underwear is to wear that over our pants. What you all say?"
And then there was a big applause.. there was bright light in their eyes and emotion level was so much high. Our stud Bat Man was trying to hide his falling tears when he was moving out. Rest is all history.