1. The first time Cas finds them, he’s just looking for socks; the bunker is cold, and his one pair had been confiscated by a disgusted-looking Dean a few days before. He sorts through various pairs, wondering if Dean has any matching ones to speak of when his fingers brush against something decidedly not cotton. It feels… smooth, and he wonders how good his feet would feel in… wow, those are not socks.
2. Castiel would be lying if he said that he hadn’t been curious about the black satin underwear he’d found ever since his fingers had brushed against them. After several feverish dreams, he decides he has to feel them again, just one more time. He sneaks back into Dean’s room when he’s out grocery shopping. Cas pulls open the drawer carefully, as if to avoid disturbing the secrets within. He opens it wide, and practically has to stoop to collect his jaw from the floor. There are dozens of pairs, folded so carefully, so lovingly. Lace, silk, cute cotton ones. Blues, greens, black, white, there’s a pale pink g-string in there too. Castiel runs his fingers gently over all of them, sighing happily, almost trapping his hand in the drawer when he hears the front door slam.