Open!
Alexander's costume would not at once be apparent. Honestly, he wasn't big into dressing up for Halloween. Last Halloween had been spent going along with Leto taking Levon trick or treating. As it was, he had almost forgotten about this little costume ball, but Leto had been good enough to remind him prior to the cruise. Of course, that didn't mean he'd gone right out and bought a costume. When Melissa had still been around, they'd gone to some costume parties dressed in couple costumes. All her idea, of course. He didn't have the desire to drag out one of those costumes from the back of his closet where they had remained, becoming rather dusty in boxes, since her death.
As such, he made his appearance at the party wearing a finely cut, black tuxedo - stylish and snazzy. It, too, was something he had not had cause to wear for a while. He was, after all, a veterinarian, and he dressed casually for that. But should anyone ask him what his costume was, he'd give them a good hint.
Stopping at the bar, he raised a brow casually to the bartender. "Martini - shaken, not stirred." It took all his composure not to break character and smirk. Oh, he could just imagine his sister rolling her eyes at him right now.