Sam, Cas, and Dean we're hunting a wendigo and Sam was making sure no one was around to see them. Dean was leaning against Baby when a bee started flying around him. He was swatting at it and Cas wasn't paying much attention. When Cas finally looked over he saw Dean about to hit the bee and got protective. He grabbed Deans hand without realizing how hard he grabbed and basically pinned it to the car.
"Ow Cas what the hell?" Dean shouted as the bee flew away. Castiel was still holding onto Deans arm with this look of rage but also confusion. "Dean you can not hurt the bee. It wasn't going to do anything bad to you." Cas was still holding onto Deans arm but he loosened his grip a little. Sammy was walking back but when he saw what was happening he decided now wasn't a good time to interfere. He walked away trying not to let Dean see him and waited behind a building.
"Bees don't have a purpose in this world so why should I let one little one live?" Dean said trying to remove his arm. Cas wouldn't let go, he slammed Dean against Baby with pure anger in his eyes. "Without bees you pethetic species wouldn't have anything in this world. You wouldn't have flowers, you wouldn't have sweets, you wouldn't have your precious pie." Cas was getting red with rage and he was basically spitting in Dean's face that's how close he was.
Sam peeked around the building and saw Cas slowly getting closer and shouting. Sam started blushing and looked back with this look of terror on his face. He's always known Dean was a closetted bisexual but he never really meantioned anything until Cas came around. The way they were always by each other and staring at each other it drove Sam crazy! He was about to walk over there and push Cas' head into Deans but when he looked back.... He wished he never did.