To make a rod for your own back

To make a rod for your own back - to do something that is likely to cause problems for you in the future.

Example - "By giving in to the kidnapper's demands, she's creating a rod for her own back"

Image - http://www.azquotes.com/picture-quotes/quote-some-people-have-a-tendency-to-get-knocked-down-in-this-business-and-sulk-and-whine-pierce-brosnan-96-13-57.jpg