Dean buying this shirt for Cas as a joke when he finally moves into the bunker and needs a new wardrobe if he’s gonna be seen around town regularly
and Dean spends like $30 plus shipping on it and thinks it’s gonna be hilarious and so worth it, but he gets it just a size too small by accident.
The moment Cas tries it on, stretched snugly over his chest and shoulders, tightly strained over his biceps, Dean immediately regrets the purchase. Fuck, he thinks, I’m gonna have to tear it off him.
But when Dean does get around to negating the point of his sartorial joke, with great enthusiasm from Cas himself, Cas still takes to wearing the shirt around the bunker.
"Hey, don’t you think by now that shirt’s not really applicable?" Dean asks one morning while they’re getting dressed.
Cas glances down at the shirt that he’s just pulled down over his head. “I’m not ‘cool’ anymore?” he deadpans.
Which makes Dean laugh and pull him back towards the bed, grinning “Nah, you’re fucking awesome,” into his lips.