Pull on my ears!

I heard this one years ago...

A couple was driving down the road when a spaceship landed in front of their car. Two aliens got out, they said, "We're a Martian couple, we came down here to have sex with Earthlings and see what that's like. Do you want to have sex with us?" The couple looked at each other and figured, what the hell, when are we going to have this chance again, so they agreed.

So, the female alien went off with the male earthling, and the female earthling and the male alien went off to do their thing. Things were getting hot and heavy between them when the male martian took off his pants and said to the woman, "Well, what do you think?" She said, "Well, to be honest, it's smaller than what I'm used to, but I guess it's ok."

The martian said, "No, no, that's not all. You see, you pull on my left ear to make it bigger. And you pull on my right ear to make it wider. That way it grows to exactly the size you like." The woman said, "oh wow," pulled on his ears, and they had great sex.

Later on, she met back up with her boyfriend and she said, "Well, how was it for you?" He replied, "I guess it would have been ok, but it was hard to concentrate because she just kept on tugging on my ears!"