Having a last minute impulse, figuring it must have to do with the celebration itself, Crowley redirected his costume, from televangelist to something a little more 'fun', overall. He was dressed only in a pair of leather pants, so tight they looked painted to his skin, and a simple black collar at his neck. His lack of shirt left his wings exposed, although he didn't feel like putting forward the effort to conceal them; especially considering the proclivity of certain people to touch, he hoped... he did enjoy the contact, when he could find it.
The real question, in his new 'slave' get-up, had been whom would be allowed to lead him. Aziraphale didn't seem keen on attending the party, which he understood as a healthy distrust of Kakia. But it left him in a bit of a bind, as to who he would trust to handle his arrival. He called his Mr. Albright on a hunch, thankful he had promised Kakia he would attend, yet planned on arriving alone. He agreed to lead Crowley into the room, to give the true effect of the 'costume', before passing his lead along to someone worthy, who would play with him for the night.
So, there they arrived, Crowley walking a step behind Edward, a relatively long leather lead (obviously made for more than one purpose) trailing between them. Hands behind his back, head down, he offered a rather convincing portrait of a submissive, as he was led into the throng of guests, in search of the hostess.