After a few years of married life, this guy finds that he is unable to perform sexually anymore. He goes to his doctor, and his doctor tries a few things but nothing works, not even Viagra.
Finally the doctor says, "This must be all in your mind," and refers him to a psychiatrist. After a few visits the shrink confesses, "Your problem is beyond me, so I am referring you to a witch doctor."
The witch doctor says, "I can cure you," and throws powder on a flame. There is a bright flash with billowing blue smoke. The witch doctor says "You are cured, but you can only get an erection once a year! All you have to do is say '123' and it shall rise for as long as you wish!"
The guy asks the witch doctor "What happens when my sex act is over?"
The witch doctor says, "All you have to say is '1234' and your erection will go away, but be warned, the magic will not work again for a whole year!"
That night the guy is ready to surprise his wife with the good news. He is lying in bed with her and says "123," and suddenly he gets a huge erection.
His wife turns over and says "Wow! How'd you get an erection?"
And he replies, "What do you think I said '123' for?"