Wincestiel 

who’s the werewolf and who’s the hunter: 
It’s always tempting to say Cas is the werewolf, but I’m gonna god with Sam and Dean as werewolves and Cas as a hunter. He was sure they were gonna eat him. (Technically he wasn’t wrong 😉 )
who’s the mermaid and who’s the fisherman:
Cas is the mermaid. Sam and Dean are poor marooned fishermen saved by some mysterious sea spirit. 
who’s the witch and who’s the familiar:
Sam and Cas are both witches. Dean’s Sam’s familiar until something really odd happens and he’s determined they both have to meet the devastatingly handsome new witch who just joined their town’s witch’s council. And a familiar’s senses are never wrong. 
who’s the barista and who’s the coffee addict:
Sam is the barista. Dean liked to come bug him and Cas is the coffee addict. Cas is cute when he’s grumpy and Dean and Sam compete to see who gets to ask him out first. (Cas beats them both to it.)
who’s the professor and who’s the TA:
Cas is a professor but so is Dean. Sam’s Cas’s TA because he wasn’t allowed to be Dean’s. (nepotism or something) But they all hang out and geek it up. Cas feels bad about having inappropriate thoughts about his coworker and TA.
who’s the knight and who’s the prince(ss): 
Cas is the prince. Dean and Sam are his loyal knights. 
who’s the teacher and who’s the single parent: 
Dean is the single parent and Sam and Cas are both teachers. Cas didn’t know they were related at first, so when he asked where Emma’s other dad was (meaning Sam) Dean’s eyes shot open. Emma thought it was funny.
who’s the writer and who’s the editor:
This one’s hard. *pout* Uh? Dean’s the writer, Sam is the editor and Cas is an artist.

Cas/Jimmy

who’s the werewolf and who’s the hunter:
They were both hunters until Jimmy got bitten. He wanted Cas to leave him in case he got out of control but Cas isn’t gonna do that. 
who’s the mermaid and who’s the fisherman:
Jimmy is a siren (not a mermaid, Cas, seriously!) and Cas is a fisherman.
who’s the witch and who’s the familiar:
Cas is the witch. Jimmy is his feline familiar.
who’s the barista and who’s the coffee addict:
Cas doesn’t function without coffee. He says that’s the reason he’s always in Jimmy’s coffee shop, but they both know better. 
who’s the professor and who’s the TA:
Cas is the professor, Jimmy is his TA because it took him a while to figure out what he wanted to do with his life. 
who’s the knight and who’s the prince(ss): 
They’re both technically princes but Cas is a better fighter than any of their knights. 
who’s the teacher and who’s the single parent:
I’m a sucker for single!dad Jimmy. Cas is, obviously, the teacher. 
who’s the writer and who’s the editor:
Jimmy is the scatterbrained writer and Cas is his editor/moral support. 

Send me ships!