How can you use Diet Pepse as a contraceptive and STD stopper?

Tell him, "Go to the store and get me a diet pepsi... and pick up some condoms while you're there."

Stick your schlong in the can. The ensuing cuts on your johnson will prevent any intercourse until they heal.

Put the bottle or can between your knees and squeeze.

Anyone who tries to have sex with you - just hit them in the head with a can of diet pepsi.

There's an urban legend that says douching with it will have that effect. You pour it in before sex or after sex, depending on who is telling the story. It is not true. Use a condom. Condoms are the only birth control methods that prevent STDs.

Since you can't spell "Pepsi" and are listening to stories, you may not know that to "douche" is to put a liquid into your vagina.
https://en.wikipedia.org/wiki/Douche
The term "douche bag", which is an insult, comes from the name of the instrument used to douche.