Two aliens landed in the desert near an abandonded gas station.  As they approached one of the gas pumps one alien says "Greetings earthling!  We come in peace.  Take us to your leader."

As there was no response from the pump, the alien repeated the greeting.  Again no response.  This greatly annoyed the alien, who considered the pump's attitude to be extremely disrespectful.  He drew his ray gun & impatiently repeated "We come in peace, damnit!  Now take us to your leader..if you refuse, I'll open fire!"

The other alien shouted "No, no!  Don't threaten him & made him mad...you don't know what he'll do!"

Too late..the first alien fired.  The huge explosion that followed blew both of them about 200 yds into the desert, where they landed on the sand in a heap.  After they recovered their senses the one who had fired turned to the other saying "What a ferocious creature!  It damn near killed us.  How did you know it was so dangerous?"

The other replied "If there's one thing I've learned during my travels through the galaxy it's this...Any guy who can wrap his penis around himself twice with enough left over to stick in his ear isn't someone you really want to fuck with!"