Pet Sex Frogs

A young blonde goes to her local pet store in search of an exotic pet. As she looks about the store she notices a box full of live frogs.
The sign says: "Pet Sex Frogs! Only $20! Comes with complete instructions." 
The blonde excitedly looks around to see if anybody's watching her. After looking at the instructions...
1. Take a shower.
2. Splash on some nice perfume.
3. Slip into a very sexy nightie.
4. Crawl into bed and place the frog down beside you and allow the frog to do what he has been trained to do.
...she gets even more excited, and whispered softly to the man behind the counter, "I'll take one."
As soon as she gets home she follows the instructions to the letter -- but to her surprise nothing happens! The blonde is very disappointed and quite upset. She re-reads the instructions and notices at the bottom of the paper it says, "If you have any problems or questions, please call the pet store."
So the blonde calls the pet store. The man says, "I'll be right over."
Within minutes, the man is ringing her doorbell. The blonde welcomes him in and says, "See, I've done everything according to the instructions. The damn frog just sits there."
The man, looking very concerned, picks up the frog, stares directly into its eyes and sternly says:
"Listen to me! I'm only going to show you how to do this one more time...."