you have to read the whole thing to get it
Two SEALs boarded a quick shuttle flight out of Dallas, headed for Houston. One sat in the window seat, the other sat in the middle seat.
Just before take-off, A Green Beret got on and took the aisle seat next to the two SEALs. The Green Beret kicked off his boots, wiggled his toes and was settling in when the SEAL in the window seat said,"I think I'll get up and get a coke."
"No problem," said the Green Beret, "I'll get it for you." While he was gone, the SEAL picked up the Green Beret's boot and spit in it.
When the Green Beret returned with the coke, the other SEAL said, "That , I think I'll have one too."
Again, the Green Beret obligingly went to fetch it and while he was gone, the SEAL picked up the other boot and spit in it.
The Green Beret returned and they all sat back and enjoyed the short flight to Houston.
As the plane was landing, the Green Beret slipped his feet into his boots and knew immediately what had happened.
"How long must this go on?" the Green Beret asked. "This fighting between our groups? This hatred? This animosity? This spitting in boots and peeing in cokes?"
Ready to Lead, Ready to Follow, Never Quit