I'm pretty sure it happened because the pissed off guy in the background of the picture wanted to make Dean his bitch, and Dean freaked out and punched him, and then the guy punched him back, right in the face, and then Sammy stepped in and was all, "Dean's already MY bitch," and the guy backed off right away because Sammy is ginormous, and now they're pretending to be prison boyfriends, and Dean keeps insisting that they have make this really realistic, because you know how he loves going undercover, so they keep having to give each other blowjobs to maintain the integrity of their cover, and when they finally break out, Sam's all concerned, like, "I guess we should stop doing this now," and Dean makes this shady argument about fighting the criminal justice system through blowjobs, and since Sammy hates injustice, he is like, "You're right. We can't stop. This is for our country, Dean." And he says it all earnestly, with a furrowed brow, and then they make out with a huge American flag waving in the background.
YOU KNOW IT'S TRUE. A PICTURE'S WORTH A THOUSAND WORDS. (here)