A/N: Another anonymous prompt from Tumblr, this time wanting a scene where Mary, Sam, and Dean find out about Cas's female vessel. This took an interesting turn into an exploration regarding angel gender. It seems to be a pretty widely debated question whether or not angels themselves actually have gender, with good points and theories from all sides. This is one of many possible explanations ^_^

Setting: Unspecified, but Mary is with them.

Summary: Jimmy Novak wasn't Castiel's first vessel. The first time he took solid form on Earth, he was a woman. The Winchesters didn't know about this, and now they're trying to understand how it all works, but it's not that simple, nor that complicated. A conversation about gender.

"Wait… what did you just say?"

From the way Dean is staring, Castiel must have said something wrong. He looks between the three bewildered Winchesters.

"I was only agreeing with Mary, females can be just as fierce of warriors as males," he stammers.

"No, the other part," Dean cuts over him. "Your female vessel?"

"Oh, that." Castiel nods. "I was saying, I prefer this vessel to my female one because females of her era wore clothes that were much more cumbersome. It made maneuvering in a fight a bigger challenge."

"Right, but you were a woman?" Mary asks, eyebrow raised.

Castiel frowns, not entirely sure how to answer. "The vessel was, yes."

"We've seen that before, though," Sam points out. "Remember Raphael? Male angels in female vessels aren't-"

"Raphael wasn't male," Castiel interrupts, brow furrowing deeper in perplexity that they don't already know this. But then, how could they? It's never really come up. "Angels are sentient masses of celestial energy. We don't have gender."

"But don't you call each other 'brother' or 'sister'?" Mary points out.

"Well, yes," he admits as he shakes his head. "Based on preference. In some ways, though, it's almost arbitrary. We weren't created male and female, though many—perhaps even most—do have a stronger inclination towards one or the other. It doesn't mean that's what we are, just what we feel. Raphael wasn't male, he simply opted for masculine pronouns."

Dean's expression is twisted in confusion as he tries to parse this out. "So… if you feel like a dude, you're a dude?"

"I'm an angel, Dean. We are not 'dudes'."

"I think what he means is," Mary jumps in, "you're not male or female, but you choose one or the other to be associated with?"

Castiel considers this. "I suppose you might see it that way, yes."

"So do you pick your vessel based on their gender, or… your gender based on the vessel?" Sam wonders.

Had he known the headache of a conversation this would spark, Castiel might have kept his remarks on vessel gender equality to himself. On the other hand, he's not used to the boys showing much interest in angel culture, and it's almost pleasant to discuss. If only he had better explanations.

"It doesn't really work like that," he says. "The vessels are largely taken based on circumstance rather than choice. Remember, I took Jimmy as a vessel first because he was the adult and the most logical choice of the bloodline, but Claire was also a viable option… except Jimmy wouldn't have it. So really, he chose for me."

"Then you don't necessarily feel more inclination to be… a guy?" Sam has a look of intense concentration, like he's reading a book of lore that he's determined to understand.

Castiel shrugs. "Personally, I don't feel one way or another, so the assignment of 'brother' is a matter of convenience for my siblings. Either is acceptable. Having been human for a while, I've dealt with both the benefits and the shortcomings of this vessel, as I imagine I would have in a woman's body."

"Huh." Dean's face is still pinched, and he shakes his head. "So you used to be a chick."

Castiel gives up. His explanations don't seem to be sticking. "Sure," he helplessly agrees, though the summary isn't really what he was trying to get across at all. He notices Sam and Mary biting their lips in apparent amusement, but neither comment or correct Dean.

There's a pause. Then, Dean smirks.

"Were you a hot chick?"

"Um," Castiel frowns. "I-I'm not sure I'm qualified to answer that question. She was very beautiful, I suppose. I don't know what the requirements are to be considered… 'hot'... by human standards."

Sam throws up his hands and walks away. Mary is snickering now, also turning for the door. Which leaves Castiel with Dean, who is still not seeming to grasp the basics of what Castiel is saying.

"So Cas, tell me more about this…"

Castiel pinches his forehead. He really should have just not said anything at all.