Calliope had decided that letting John and Jane plan a birthday party probably wasn't the best idea. Letting them plan a combined party for Rose, Roxy, Jade, Jake, Dave, and Dirk was really not the most thought-through plan. While she was far from an expert on regular human culture, Calliope was pretty sure renting out some sort of pizzeria was not a common 17th birthday venue choice. But she was neither the host nor recipient of the party, so who was she to judge? Besides, that wasn't even her biggest problem.
Calliope felt out of place.
It wasn't because she was the only non-human there, because she wasn't. There were plenty of trolls that had been invited by various people (Vriska, Terezi, Karkat, Kanaya, Meenah, and Aranea were all present, as well as a few more she didn't know very well.) It wasn't because she was sitting alone (mostly). But it was because she wasn't as connected as everyone else was. They were all interrelated and inter dating (her inner shipper still would squee on occasion). They had all been through the game together, and had lived and died together. Calliope had been interacting with them yes, but she wasn't like them. She never got to actually enter the game, and she never lived or died in the ways they had.
But worse than all that, was her appearance. Calliope had always hated her body, with its dark green color and hard body texture. But once she had died, she was happier. In the dreambubbles, she could hide and change her appearance and become whatever she wanted. But now that she was alive on earth, she remained once again in her cold, green shell. And it worse this time, because every time anyone looked at her Calliope knew they were seeing Caliborn. Caliborn who had killed (or nearly killed) every person at the party. Caliborn who-
"Heyo Callie! Howya doin?"
Calliope jumped at the should of her friend's voice. Roxy was now sitting across from her, a wide smile gracing the girl's features.
"I am doing quite fine Roxy. How are you enjoying your birthday celebration?"
Roxy's grin only seemed to get brighter. "Its so fantastic that everybody came! And getting to party with all my friends is so amazing!"
Calliope couldn't gel but feel herself smile. Roxy had always had such an infectiously happy energy, even when she was just pink text on a screen.
"That is fantastic Roxy. It is very important to be surrounded by loved ones an days such as these."
"Callie." Roxy's face was now serious, a look Calliope had always thought looked out of place on the fun-loving girl's face. "Callie, are you really enjoying yourself? I know you've been sitting here like a mope, and I don't want you feeling lonely. You're one of my closest friends, I want all my friends to have a good time!"
Calliope could feel the faint ache of tears brewing. It was such a simple sentiment being expressed, but it meant so much. "I- Thank you Roxy. I am feeling quite good now, and not at all lonely."
Roxy's wide grin returned. "That's great! Come here!" She reached out and grabbed Calliope's arm. "We're going to go play some of those arcade games. I'm super boss at some of these, but its way more fun with other people."
"That sounds brilliant. Let us go do that!"
Roxy giggled and pulled Calliope over to the mini arcade. Six different games lined the wall, with only one in use (Jade and Dave were playing the shooting game- Jade seemed to be scoring highly, Dave seemed to be really struggling).
"Let's play this one!" Roxy walked up to a machine labeled "Rampage World Tour." The cabinet for the game seemed to be faded at slightly beat up- it was clearly one of the older games in there. Roxy grabbed at the rightmost joystick. "I want to play as the giant wolf thing. You can play as the giant lizard or the giant monkey."
"I believe I would like to play as the lizard."
Roxy smiled. "Then here, grab the middle joystick." As calliope positioned herself in front of the middle station, Roxy bent over to enter another coin into the machine.
As the game began, Calliope found she was better at this game than she thought she would be. She had expected to have the character flailing around, but she actually was doing alright. She assisted Roxy in getting to the 3rd level before they both lost, resulting in the giant mutated animals shrinking down into embarrassed naked humans.
Calliope smiled widely "Can we play another game, this was very fun."
Roxy smiled just as widely "C'mon, let's go play Dance Dance Revolution. It's gonna be fantastic"

So this fic idea came from one of the prompts I was given: "Roxy takes Calliope on a girl's day out. They then return home for a girl's night in. Bonus for video games/arcade games." While this is not really anything like that prompt, I got really stuck on the idea of arcade games. And the only place I ever really played arcade games on any sort of regular basis was at Round Table Pizza- a small pizza place in my neighborhood. Rampage World Tour is a real game, and I played it many times (I wasn't very good at it, mostly because I would try beat up who I was playing with, not the buildings like I was supposed to)
The only idea I really wish I could have included was my headcanon for cherub digestion systems. Pizza doesn't cooperate well because of all the cheese and tomato and dough, so Roxy would have ordered Calliope a like mega meatlovers pizza. Like everything but crust was meat.