Abstinence - Disadvantages of Abstinence

What are the disadvantages of Abstinence?

If you're planning to use abstinence, and change your mind in the heat of the moment, you might not have birth control handy. Some people would like to be prepared and have a condom or spermicide available in case they change their mind. Others feel that having a contraceptive ready and available might tempt them.
It may be very difficult to communicate clearly with a partner about abstinence
Some people find not having sex too frustrating, and may feel as though they are "missing out".
If only abstaining from penis-in-vagina intercourse, there may be no protection against infections transmitted through other activities such as oral and anal intercourse, including herpes, genital warts, gonorrhea, and HIV/AIDS.
Some who choose to no longer abstain may have little knowledge about other methods.