It rained the next day, and Cas stared out the window, looking sad.

"What's wrong?" Dean asked. He really hated and loved Cas's expression right now. He looked like a sad puppy that wanted to go outside and play.

"It's raining." Cas grumbled. "We can't do something off the list today."

"Why not?" Dean grinned. "Or was rain not on the list?"

"Why is rain a simple thing?"

"Well, no one really stops and appreciated so that it does for us! It waters plants, washes your car, and creates fun puddles to jump in."

Cas's eyes widened.

"Can we go jump in puddles?" He asked eagerly. Dean grinned.

"Of course we can, buddy."

Ten minutes later, the pair was walking down a street, Cas jumping in every puddle, letting the rain soak his clothes. Dean was a bit more dignified as he hid under his umbrella. It was pouring after all. He hadn't seen it rain this hard since he and Sam were working a case in Iowa.

"Come on Dean!" Cas insisted, jumping into a puddle and splashing the Winchester. Dean yelled and jumped back, like a furious wet cat.

"Oh, you'll pay for that one." Dean declared, closing the umbrella. The cold rain instantly soaking him and his clothes. Cas shrieked and ran away as Dean chased after him, brandishing the umbrella like a bat.

The two splashed in the puddles for hours, and eventually ditched their heavy, waterlogged coats on a bench. It was a bit cold, in Dean's opinion, to be running around in just a t-shirt and jeans, but the activity warmed him up.

As well as the sight of Cas's white button down clinging to his skin.

Dean shook himself. What was he thinking?

You're thinking that Cas has your vote in the next wet T-shirt competition. His brain reminded him.

Shut up brain. He yelled back, but his gaze lingered on Cas, taking in his wet hair that was even messier then usual, his glowing blue eyes,  his chest, his....

I'll shut up when you take that shirt right off him. The pants wouldn't hurt eith-

"Dean?" Cas asked, jolting the hunter out of his thoughts.

"Huh- what?" He stammered, trying to rapidly think of an excuse for why he's been staring.

"Want to go back to the bunker?" The angel questioned, tilting his head the way he always did when he was confused.

"Sure thing Cas."

After they returned to the bunker, Dean immediately took off his shirt, heading to go find dry clothes.

Cas watched him walk away, admiring the view.

Once he was gone, Cas checked the list to see if there were any more items they could cross off today.

There was one.

And that was how Dean ended up finding Cas kneeling on the floor of the bathroom, still in his soaking wet clothes, staring at the toilet.

"Uh.....Cas?" The hunter asked, not sure where to even begin with this.

"Sit down with me, Dean." Cas insisted. "We must appreciate the wonders of indoor plumbing."

Dean stared. But, then again, he had done weirder things in his life. So he sat down next to the angel, and watched the toilet.

"....How long do we have to appreciate it for?" Dean asked after a few minutes.

"However long it take for the message to sink in." Cas replied. Dean glanced over at the angel, and all thoughts of studying the toilet went out of his head.

He stared at Cas's face, memorizing his eyes, his nose, spending a full minute just watching the angel's lips. His gaze slowly drifted downward before rising and resting again on Cas's hair. 

It was a while before the innocent angel noticed. But once he did, he turned his head toward Dean, frowning in confusion at the hunter's deep thought.

"Dean?" He asked, looking curious. The hunter's stare intensified, focused on Cas's mouth.

"Oh, screw it." Dean swore before grabbing Cas by his wet tie and kissing him. 

Cas's eyes went wide, but he leaned into the kiss, deepening it.

They paused after pulling away for air, staring at each other.

Dean swallowed hard, trying to rid his mind of all his dirty thoughts.

"Maybe we should get you some dry clothes." He whispered. Cas barely nodded, still watching Dean.

Rainy days, the angel decided, were his favorite.