Dionysus was up for a party. There were serious things going on lately that gave him a headache when he attempted to think about them. Which generally meant that he didn't do a great deal of thinking about them. Dionysus wasn't the sort very prone to deep thinking, though he was sometimes strangely philosophical and insightful when he was very, very drunk.
But a party didn't require thought. Except for thinking of what to wear. Which wasn't really that difficult to figure out either. Dionysus saw no point to a party with masks where you weren't in full costume. And since the mask meant he wouldn't be recognized. . . well maybe. . . he just didn't especially care if he was.
Which was probably why he arrived fully dressed, a white feather mask over his face, a wig on his head, and a slinky white dress that looked a great deal like something he thought he might have seen on Hera, once, complete with shoes, even if his feet would start killing him soon and be abandoned, and fairly realistic looking fake tits.
He was a fairly attractive guy. Dionysus was not, however, THAT attractive of a woman, as it turns out. Or at least not tonight. In his more high-powered godly days when he'd made the switch, he'd pulled it off more impressively.
Of course no one would probably KNOW that he was supposed to be Hera. But Dionysus knew, and he thought it was funny, so that was really all that mattered.