Dean def indulges in some pretty raunchy dirty talk/flirting (it is hopelessly porny and cheesy). But Cas, who is so deeply enamored with Dean, thinks it’s the hottest thing he’s ever heard and it never fails to get him all riled up. But like, from an outsiders perspective it’s just BAD. Like Sam walked in to the bunker kitchen to find Dean under the sink, fixing away, with Cas watching him work and helping by handing him things. He froze in the doorway when he saw Dean PURPOSEFULLY flip over on to his stomach with his shoulders still in the cupboard and pretend to be ‘stuck’. Then, he saw Dean arch his back and begin complaining in a WAY too excited voice that he was stuck and needed some “rigorous motion” to help shake him loose and that he needed the angel to “take a turn checking HIS pipes”. Cas looked alarmingly into everything Dean was saying and was already shrugging off his trenchcoat and after that Sam just spun on his heel and tried to mentally block ever seeing and hearing that.