"What are these?" Dean questioned, looking at the paper decorations Cas had hung on the wall of their dorm room. Cas glanced at Dean and tilted his head in mild surprise.

"They're Halloween decorations." Cas replied, peering at the paper bats and ghosts he had hung on the wall. "Don't you put up Halloween decorations at home?"

Dean shook his head, setting a plate down on the table. "I was lucky just go get a costume. My family, we didn't celebrate Halloween much. We'd go trick or treating every couple of years, which I always enjoyed."

Cas bit his lip awkwardly, sensing not to press the matter further, and turned his head. "My family loves Halloween. My eldest brother always went all out for the holiday, he helped my parents decorate the house since he was 9."

"Your family sounds fun."

Cas cocked his head, briefly glancing at the ground, before he turned to face Dean. "My family's hosting a Halloween party on Halloween, and us family members can bring two people along. I can bring you with me, if you want."

"Sure, as long as I can bring my brother with me."

Cas nodded, and grabbed his wallet. "I'm going out to get some more food. You want anything?"

Dean perked his head up. "Ice cream and bacon."

Cas shook his head as a small smile crept onto his lips. "Alright. I'll be back in half an hour." Dean smiled and nodded, and Cas stepped out the door.

Dean turned back to focusing on the homework that he had left sitting on the table. It was for his Calculus class, which was his least favorite class, as it was the hardest. He drummed the pencil against the desk in a frustrated manner, his eyes gazing at the questions on the paper. He didn't understand how anyone could get this.

As the minutes passed, Dean gave up and decided to rummage through the pantry. Then, when he remembered that Cas was out getting food, so he settled onto the couch and grabbed the computer Bobby had gifted him back when Dean had first moved to the town. Dean went onto Netflix and scrolled through random movies, trying to find a good one to watch. By the time he settled on a movie, Cas had returned and walked through the front door.
"I have food." Cas murmured, holding up a bag of fast food. "I got you some breakfast from a restaurant on my way back home."

"You're a lifesaver." Dean exclaimed, grabbing the bag of fast food as soon as Cas handed it to him. Cas also handed him a drink, a soda he had bought alongside the food. Dean thanked him again before he began devouring his food. Cas even smiled when he saw how eagerly Dean ate his food; he reminded Cas of the childhood dog he had had, always eating every meal as though he had never eaten before.

"Don't eat too quickly, you'll get sick." Cas remarked as he set his grocery bags down. "I know you must be starving, but don't inhale the food."

"If I get sick from eating then that's the price I have to pay." Dean commented with a mouth full of food. "It's better than going hungry."

Cas shook his head, a small smile curving onto his mouth. "Your food isn't going anywhere. It's not going to disappear if you don't eat it within two minutes."

Dean paused, a fleeting, unpleasant memory filling his mind. Dean shook his head, finishing off his food with another huge bite. "You don't know that." Dean murmured as he stood up to throw his trash away. Cas heard the small remark, but didn't think much of it. Instead, he just started putting up the groceries he had gotten in the small dorm room pantry.

Dean still had a somewhat upset look on his face, and Cas, while not incredibly perceptive, quickly picked up on it.

"Hey, Dean. My older sister invited me to go with her to this aquarium in the town over, do you want to come with me? My sister won't mind."

Dean turned his head, locking eyes with Cas. "Uh, sure. I've never been to an aquarium."

Cas tilted his head. "Well, you'll love this aquarium. I've been there, it's actually quite intriguing." Cas seemed to pause, and added an afterthought. "And my sister's nice. You'll like her, I'm sure."

"What's her name?"

"Anna. And she has red hair, and she's very competitive."

Dean hummed, then stood up and looked at Cas. "Alright. When will we go?"

"Anna wants me there in half an hour, so we should leave in ten minutes."

Dean hurried to change, putting on a new jacket and some jeans. He patted his hair a little, as it was sticking up some. When he came back out of the bathroom, Cas was typing on his phone. Cas lifted his head at the sound of the door opening, and a pleasant smile formed on his face, one that made Dean smile.
"You ready?" Dean nodded, and Cas tossed Dean his keys. "Alright, lets go."

Dean and Cas climbed into Dean's car, and Dean began driving to the aquarium, Cas guiding him down the correct streets.

Meanwhile, the two struck up a conversation about their respective classes while Dean played rock songs on low volume. Surprisingly, Cas didn't seem to mind the rock songs, and he actually nodded his head along to the rhythm.
They quickly reached the aquarium, and Dean pulled into a decent parking spot. The two walked to the front of the building, where a young woman with red hair stood waiting.

"Castiel! There you are!" The woman exclaimed, running over to hug her younger brother. As she pulled away, she glanced at Dean. "Who's this?"

"Anna, this is my roommate, Dean Winchester."

"Mm. You single?" She remarked, and before Dean could respond, she shook her hand. "I'm just kidding. It's nice to meet you."

"It's nice to meet you too." Dean spoke, as she ran a hand through her hair. Anna gave him a sweet smile before turning to Cas.

"I have dinner with Michael at 6, so we have to leave by 4, alright?"

Cas nodded, and Dean, intrigued, looked at Anna. "Who's Michael?"

"Our older brother's boyfriend." Anna explained. "He had the same major as me, so I'll meet up with him occasionally and he'll help me with some of my assignments."

As the trio walked into the aquarium and paid, Dean continued to strike up a conversation with Anna. "What's your major?"

"English."

"Dean." Cas murmured, catching Dean's attention. Cas pointed to a tank nearby, the closest one to the entrance. "It's a tank, look."
Dean was in front of the tank in an instant. The tank was full of some saltwater fish, nothing too intriguing, but Dean seemed enamored enough by it. Cas smiled; Dean seemed so awestruck and amazed by something so simple as a saltwater fishtank. It was.... almost amusing.

"Do you like the fishtank?" Cas questioned, as if he couldn't already predict Dean's answer from his expression. Dean nodded eagerly, and Cas held back a chuckle at the raw curiosity and awe Dean had.

"Haven't you been to an aquarium before?" Anna questioned, tilting her head.

Dean shook his head, his attention still primarily focused on the fish. "I've never been to one. Never had enough time as a kid."

"Huh. Your family must've been one busy one, then." Anna remarked, placing a hand gently on the glass of the tank. She peered in, her attention caught by one of the more colorful fish.

"My family has always been busy." Dean mused, not knowing Anna was no longer listening.

"Cas, look. It's a queen angelfish." Anna muttered, tapping her younger brother on the shoulder. "Look how colorful."

Cas nodded, his eyes lingering on Dean, who was still enamored by the fish in the tank.
"Dean, there's more tanks if you want to see them." Cas spoke, and Dean's head whirled around. Cas held back a laugh at how quickly he had caught Dean's attention.

"Hell yes."

Dean followed Cas over to the otter tank while Anna continued to fawn over the colorful fish in the saltwater coral reef tank. Dean, while he refused to admit it, cooed a little over the otters, a sort of childlike glee filling his face. Dean had rarely ever gotten the chance to just relax and do something fun, like going to an aquarium.

His eyes began to scour the crowds, spotting families with young children and couples holding hands. It suddenly made Dean very grateful he had Cas next to him, though a bit resentful that he couldn't hold hands with Cas like he wanted. As Cas pointed out a few of the otters, Dean laughed, and Anna watched with a sort of curiosity from where she was.

When Cas walked off to go to the bathroom, Anna tapped Dean on the shoulders.

"Hey, Dean. Can I ask you something?" She asked, her head tilting to the side a bit, just like how Cas's would. Seemed that the head tilt was something that ran in the family.

"Hm?"

"Are you in love with my brother?"

Dean spluttered, caught off guard by the sudden and all-too surprising question. He was about to answer when Anna gave him a knowing look, and he sighed, defeated.

"Yes."

"Mhm." She murmured, brushing a bit of her hair off her shoulder. "Well, my brother is a bit too oblivious with feelings, so good luck. But if you hurt him, I'll end you."

Then she walked off to another tank without a word, and Dean was left red-faced, his eyebrows raised. Cas returned quickly, and Dean remained quiet, observing the otters while he mulled over thoughts in his mind.

Cas, however, soon proved to be enough of a distraction to bring Dean out of his thoughts.
The two boys walked around the aquarium for quite a while, Cas pointing out tanks while Dean would clamor over them. Cas nearly laughed a few times; it was far too amusing to watch Dean get so excited over something as simple as a fish tank. Then again, from what Dean had said so far of his interests and experiences, it seemed there was still a ton of things he hadn't yet done that most people had. Towards the end of the day, they bought some snacks and sat on a bench, eating and chatting. And both of them could agree that it had been an incredibly fun day.

I managed to write Anna into the story! Also, more fluffy destiel moments before they're even together. I haven't actually been to an aquarium in a few years so I wrote it based off my memories of the aquarium in my hometown.
~ Liz