Cas had been acting weird lately. He would blush randomly, stutter, get all sweaty, and just pop out mid-coversation. Well, okay. That wasn't new, but it happened more frequently. Dean wondered at first if Cas liked someone, but then it started happening when it was just them. Alone.
One day, during a particularly difficult demon hunt, Cas and Dean were alone. This wasn't abnormal as Sam would usually be the one doing research at the library. Cas started getting all awkward and clammy again.
"What is it, Cas?"
"Umm... Nothing. Forget I said anything."
"All right. Well, this thing's hunting grou-" Dean was cut off by soft lips hitting his. He stood frozen in shock for a minute. Then, Cas pulled away, his checks burning. It took Dean a little while to register what happened, but when he did, he was furious.
"What the hell man? You can't just pull a stunt like that outta the blue? I mean..." Dean was at a lost for words.
"Look Dean, I'm sorry I..."
"You're sorry?! YOU'RE SORRY?! Man, how..." Dean took a few moments to calm down.
"You've seen how I am with women. Hell, I look for women almost every night I'm not working a case. Why the hell would you think I would swing that way?"
Cas was starting to get angry He just didn't understand. Sure, it was fine Dean didn't feel the same... well, no it wasn't. But still. Why did he have to yell at him like that?
"Even if I did feel the same, you can't just kiss people without warning!"
"Why not? Had you felt the same, would you not have encouraged it?"
"But you didn't know! How could you possibly know?"
"Because you look at me every chance you get. Because you stood up for me after all the mistakes I've made. Because you like it when we're alone together. I can see it in your eyes, Dean. It's obvious." They were both yelling at this point. Neither of them wanted to fight, yet they kept on yelling.
"You know what? Just leave. Sam and I can handle this case perfectly well without you. I don't care where you go, you just need to leave." Dean turned around. How could Cas be so stupid as to think... It was just ridiculous. He heard the woos sound of wings and knew Cas was gone.
