Two aliens landed in the New Mexico desert near a gas station that had been closed for the night. They approached one of the gas pumps and the younger of the two aliens addressed it. "Greetings, Earthling. We come in peace. Take us to your leader."

The gas pump (of course) didn't respond. The younger alien started to get mad at the lack of response and the older one said, "I wouldn't do that if I were you."

The younger alien ignored the warning and repeated the greeting. Again, there was no response. Annoyed by what he perceived to be the pump's haughty attitude, he drew his ray gun and said impatiently, "Greetings Earthling. We come in peace. Do not ignore us in this way! Take us to your leader, or I will fire."

The older alien again warned his comrade, "You don't want to do that. You really don't want to make him mad!"

"Rubbish," replied the younger alien. He aimed his weapon at the pump and fired.

There was a huge explosion. A massive fireball roared outwards and towards them and blew the younger alien off his feet and deposited him in a burnt and crumpled mess 200 yards away in a cactus patch.
Thirty-five Earth minutes later, when he finally regained consciousness, refocused his three eyes and straightened his bent antenna, he looked dazedly up at the wiser one, who was standing over him, slowly shaking his big green head.

"What a ferocious creature," said the young fried one. "It damn near killed us! How did you know it was so dangerous?"

The older alien leaned over, placed a friendly feeler onto the crispy, peeling flesh and shared some knowledge. "If there's one thing I've learned during my travels through the galaxy," said the wise old alien. "When a guy has a penis he can wrap around himself twice and then stick it in his ear, you don't mess with him."