"I mean, you’re–” He gestures at Cas, in his neat oxford shirt and nice pants. “–and I’m a high school dropout who tattoos for a living.” Wherein Dean makes a hefty living as a tattoo artist who owns the space next to Gabriel's cafe. Sam attends the local university. When Gabe's cousin comes to live with him while starting grad school at Sam's university, Dean thinks for sure that all his negative karma's coming to bite him in the ass because Cas clearly has a thing for Sam. No one would ever choose him over Sam. That's just logic.