Rosciel:
Rosciel was, for the most part, casually dressed. At least, it felt casual to him. Suit pants and dress shirts alway felt comfortable and loose to him. And his regular shoes felt somewhat like the shoes he normally wore. So, needless to say, he didn't have any problems wearing a dark red dress shirt and black suit pants. He sometimes wore a jacket with it, but he figure that would be too much for this occasion.

He stopped outside of Arachne's room and lightly knocked on the door.

Arachne:
Arachne was actually ready before Rosciel knocked on the door but it never hurt to make a boil wait, even a non-date one. She called out;
'Just a minute!' and then proceeded to rebrush her hair and fiddled around with her bag, making sure that she had her tarot cards before going to the door and opening it.
She looked the boil up and down, before saying;
'You'll do.' and grinned, leaving her room and shutting the door behind her, careful not to trap the train of her dress as she did so.

Rosciel:
"You don't look so bad, yourself," Rosc replied with a small smirk and actually offer her his arm. If he was going to play the part of the proper escort, then he would certainly act like one. Of course, as soon as they parted ways, he was going to go back to his usual ways. A drink and a good place by the doors.

"Ready to go?"

Arachne:
'Well thank you, and as it comes from you, I will take that as a very big compliment.' Arachne took his arm, feeling a slight thrill at doing so. This was after all the closest she'd gotten with a boil, and even if it was one that she was only turning up to the party with just so she didn't arrive alone, it still registered as a new experience.

'I am.' she actually smiled up at him, and added;
'Lets go then.'

The party was not too far away she knew, and so he wouldn't have to put up with her terrible presence for too long.