Esther opens with a description of the king's party, including all the drinking going on in the courtyard, and then it says (1:9):
Queen Vashti also made a party for women, in the palace of King Achashverosh.
What were they doing there?
The Midrash (the Yalkut Shimoni) explains that women like to know everything, so Vashti gave a tour of the palace, pointing out where the king slept, ate and drank, leading her guests though the painted rooms...
"for as Rabbi Avin said, a woman would rather look at pretty things than eat fatted calves."