Rorie was mentally an vocally cursing his brother. He had wanted to just go chaperon the college and high school parties, but Finn had insisted they go to the staff party. There were people there that Finn didn't want to see or run into probably, but that didn't deter the older brother from getting his little brother dressed up and out the door. Rorie's plan was to find a nice dark corner and drink himself under the table. Garret would probably be there and they were doing a space thing. That didn't mean he wanted to see the other with anyone else. Mark hadn't wanted to go because he didn't like dressing up. Apparently he was sensitive about people dressing up as a werewolf and making fun of them. Rorie didn't argue, just said okay and gave in to letting Finn fix him up as the Joker.
Finn himself was the Riddler and Lily joined the comic gang as Harly Quinn. That kind of brightened Rorie's mood, but not by much. When they arrived to the party it was in full swing. People were dancing and drinking and eating and talking. Artfully sneaking away, since Rorie had mastered that skill by now, he found himself a drink and stood against the wall next to a grim reaper who he wasn't sure was real or a prop. Finn quickly found the punch and started to chat up a few people who remembered him and didn't have awkward encounters with. Mostly other cleaning and behind the scenes faculty.