"Double dippers" refers to people who repeatedly take advantage of a situation or resource that they have already benefited from, typically without contributing or giving others a fair chance to benefit as well. Full definition
Just don't put spoons in the same room, because you'll be sharing germs with double dippers in no time! (realeverything.com)
Glad you are not opposed to double dippers as I am going back to work again. (nystateofpolitics.com)
You should put someone up in albany to primary that pension double dipper who has been in office for two decades and has nothing to show for it! (nystateofpolitics.com)