double standard
noun
- application of different sets of justifications for situations that are essentially the same
Wiktionary
noun
- The situation where two groups or individuals are the same in pertinent ways, but one is condemned for it while the other is excused.
“For example, when discussing relationships, she admitted that she believed in a "reverse double standard".”
- A pair of monetary values, i.e. a gold standard and a silver standard, both of which are legal tender.