Castiel couldn't understand the anger Dean always exhibited when he appeared in the room with the brothers. Nor could he explain how, despite having no wings in this form, the sensitivity when they stood side by side, or how Dean's anger made the sensation of his phantom appendages feel electric. He imagined that if they were visible they would surely be fluidly rippling and flaring; thrown out to their full width in the Winchester's presence as if acting on their own.

Dean infuriated Castiel; the human was obnoxious and irrational, rude and pushy; Yet Castiel found himself exhilarated by the rush Dean gave him. Castiel wanted to test Dean's strength, match Dean's control and power to his own. He wanted to find an equal in him.

It frustrated him that so much of his desire lay in Dean's actions, and that the other angels would ridicule him for yearning for the equal of a human. There was no comparison in most angels' minds; Humans stood even below demons in the power struggle, little above animals. Castiel saw everything he'd previously believed in challenged by Dean Winchester. Dean Winchester had the potential to be his equal.

He found Dean brooding in a bar over a failed hunt. The angel could tell he wasn't drunk though he certainly wanted to be.

"Dean," He said, reaching out to him tentatively.

"Cas!" Dean yelled, earning several looked from other patrons as Dean almost fell from the bar stool. Cas' hand steadied him.

"Perhaps you should return to your motel room," Cas suggested.

"Whatever," Dean shrugged, but complied as Cas pushed him gently towards the door.

"Where are you staying?"

"Baby,"

"What?" Cas said turning on him,

"My car," Dean emphasised as if it were obvious. Cas frowned.

"Where is it?"

"Two streets over," Dean said, sighing and taking the lead. Cas kept speed with him until they turned a corner and he saw the impala.

"Hey baby," Dean said fondly, striding towards it, fishing the keys from his pocket before turning back to Cas. "Okay Cas, babysitting duty is over, I suppose that's what Sammy asked you for,"

"I came on my own accord,"

"Yeah, 'cause you enjoy my company so much when don't need each other's help,"

"You have caused no trouble for me, I would not have been involved with eventually,"

"Cas. Get out of here," Cas cocked his head to the side,

"What would be the point of me coming here of my own free will to simply be ordered away,"

"Stubbornness?" Dean suggested as he opened the car door and flopped on to the front seat.

"I am not stubborn," he said, leaning one arm on the roof looking across at Dean.

"Cas you're as stubborn as a five year old,"

"So you keep informing me,"

"It's the truth. You'd see through my lies anyway," He says, rambling a bit as the tiredness and alcohol relaxes him.

"Your truthfulness infuriates me sometimes,"

"Your arrogance, because I'm an Angel of the Lord routine, infuriates me," Dean said glaring up at Cas.

Cas grabbed his shirt with one hand and hoisted him out of the car and threw him against it, feeling guilty as he saw Dean wince.

"And I suppose you Dean Winchester, never get arrogant and cocky when he has an angel backing up his endeavours,"

"Half the time I have to keep said angel in line, the other half of the time he refuses to involved in our petty human affairs," Dean argued and squaring up to the angel.

"I do everything within my power; just as you do," Dean frowned and stared eye to eye with Cas's face.

Dean had come to do this more often, studying the angel's face, his expressions only given away by the twitch of a muscle. Cas enjoyed being the subject of Dean's intense attention, when Dean became so still when Cas knew he was learning his vessel's body and habits.

He wished Dean could look upon his true form instead of this vessel, though perhaps he would be repulsed. Cas knew his battle torn wings, mismatched in dark shades were a long way from the purer feathers the other angels more highly regarded. He imagined Dean would have similar dark wings to his own. He took a deep breath, still looking at Dean; it was a proud stance. Cas was surprised when Dean backed away.

"Cas, I'm sorry, I didn't mean to, I'm sorry," Dean stumbled and Castiel caught him. Dean flinched as if Cas were about to hit him

"Why are you so afraid?"

"Your wings Cas. Definitely a bad omen," He said, still trying to back away but held in an iron grip.

"You can see them?" Cas said, astonished.

"Only when you're seriously pissed at me,"

"You've seen them before?" Dean nodded. Cas glanced behind but could see no wings protruding from his vessel. "Can you touch them?" Cas didn't know what to expect when Dean reached to a spot just behind his shoulder. A ripple like a static shock made Cas shiver. He looked at Dean who was now running his fingers along the very top to the tip of where he could feel his wing.

"Is this as far as they reach?" Dean asked. Cas concentrated on how it would feel to stretch his wings to their full potential. It wasn't done often; only as a demonstration of power or a mating show. He saw the tug on Dean's hand where he held the invisible limb.

"I'm not sure if I can stretch them out with you holding it there,"

"They faded after I first touched them; I don't want to lose where they are,"

"When else have you been able to see them?"

"A few times. Like I said, you were usually pissed off at me. When we were shouting, arguing, once when you told me you didn't have the faith in me to do the right thing like Sam did. They looked different that time: smaller, heavier, like they were covered with some sort of liquid or oil," Tears of an angel, Cas refrained from telling him; tears of betrayal that covered the wings. Cas tried to remember the other occasions Dean could be talking about. All times when they had been arguing meant that he was being challenged by Dean. He was distracted when Dean felt his way deep between the feathers to the sensitive skin beneath. Cas gasped.

"I thought you said the human vessel couldn't survive parts of your true form like this?" Dean asked.

"It can't. I didn't know you could see them. I can't see them, but I can feel when you touch them, I only bring them into my wavelengths of sight when I'm grooming them"

"And you can control them?"

"If I concentrate,"

"So they are most present when you exhibit power. Should I start shouting again?"

"I don't think it works like that,"

"Then fight me," Dean suggested and Cas eyed him warily.

"I regret it when I use physical force with you,"

"I could take you any day," Dean said with a twitch of his eyebrow telling Cas to do no less than 'Bring it,'

"Unlikely," He said just as Dean tackled him and threw him to the ground.

"Dean! Dean, stop it!" They tussled until Cas leapt back with a yelp and Dean sat back, a satisfied grin on his face. He held his prize up to Cas; a long black feather with a navy blue tint as it caught the street light. Cas looked away embarrassed as Dean ran the feather through his fingers, unaware of the cultural significance of stealing such a possession.

"You can't keep that,"

"Why not? I can't put it back,"

"In angelic culture it is either an aggressive move to steal a portion of another's wing, or an affection one,"

"It's a feather Cas,"

"But you took it from me,"

"You let me touch your wings,"

"I admit I was forgetting myself,"

"So that would have been affectionate too?"

"You were fondling my most sensitive limb, Dean. What do you think?" Cas snapped at him. Dean hesitated and then reached out.

"I want to do it again," Cas shuddered and leaned into the touch.