Set somewhere in series 6 after Sam has his soul back.
--
Dean was just sitting, there thinking about random thing when the realisation hit him.
"Gabriel." He said bluntly, looking over at Sam.
Sam's head snapped up. "What about him?"
"He's your soulmate, isn't he?" Dean questioned.
"A whole year. You're an idiot, Dean." Sam muttered. "It took you so bloody long to figure that out."
"So he was?"
"Yes, he was. Now shut the hell up, okay? I don't want to talk about him, please." He whispered.
"I'm sorry, Sammy."
"Yeah, me too, Dean."
--
And here's another update, because it's extremely short, so what the hell, have it.