Hey Nineteen

"Hey Nineteen" is a song by the band Steely Dan from their album "Gaucho" (1980).
Background.
According to one reviewer's interpretation, the song "was about a middle-aged man's disappointment with a young lover":
The song's bridge suggests there is pleasure in the relationship as well, though the song is ambiguous enough to suggest the song's protagonist is indulging by himself.
"Colombian" is another name for cocaine from Colombia. In the 1960s, "fine Colombian" was marijuana.
Charts.
"Hey Nineteen" peaked at number 10 on the "Billboard" Hot 100 chart in early 1981, number 11 on the Adult Contemporary chart, and number 68 on the R&B Singles chart. With a chart run of 19 weeks, "Hey Nineteen" is tied with "Peg" and "Rikki Don't Lose That Number" for being their longest-running chart hit.