One of the themes of Purim has to do with the hidden becoming revealed. Esther hid her identity as a Jew within Achashverosh’s castle. When the time was right not only did she reveal her true self, but she revealed Haman’s evil plot to destroy the Jews. All the coincidences within the story of Esther all come together in the end and reveal a rich and interesting story. G-d’s name is not mentioned at all in the Megillah (Scroll) of Esther, but is hidden within Esther’s name itself, which means Hidden.
My husband and I celebrated Purim with a local Jewish organization. I dressed up as Time Flies (I had wings and clocks) and my husband dressed up as Father Time. Father Time was a priest with clock picture on his chest. We felt this was funny on a few levels, since my husband isn’t Jewish. I think he appreciated being dressed up as a character that is distinctly not Jewish. He could be his non-Jewish self openly when all through the year he feels like he has to downplay and maybe hide the fact he isn’t Jewish.
We had agreed that our son would be raised in an entirely Jewish environment and my husband isn’t/wasn’t very religious so it didn’t seem like a big deal. It does mean though that he gets submerged and swallowed with Jewishness. Kosher food, Shabbat meals, Jewish holidays… he’s surrounded all the time.
We celebrate Purim by hiding behind masks and pretending to be what we aren’t (or briefly live a fantasy of who we would like to be), just as Esther pretended she wasn’t Jewish. My husband got to enjoy the party being openly non-Jewish.