A man flies to Africa to track down a medicine man with a cure for impotency.
The medicine man instructs, "You will now have three chances for an amazing erection. When you say or hear 'Towomba,' you'll experience a massive erection, but when you say or hear 'Sobiga,' you'll lose the erection. Remember, only three chances!"
The man flies out of Africa and on the plane, the pilot announces, "Thank you for flying with us at Towomba Airlines." Immediately the man has an erection and says, "Sobiga," to lose the erection.
Upon landing, the pilot announces, "Thank you once again for flying with us at Towomba Airlines, hope you had a pleasant flight." Once again, the man has an erection and has to say, "Sobiga."
Knowing he has one chance left, he rushes to his girlfriend. He strips off his clothes, says, "Towomba," and gets a massive erection. When his girlfriend sees his enlarged penis, she says, "Wow, so big... ah!"