The “dirty lowdown” is the honest truth – what Scaggs is encouraging this poor sap to face. 

Baby’s into running around, hanging with the crowd
Putting your business in the street, talking out loud
Saying you bought her this and that
And how much you done spent
I swear she must believe it’s all heaven sent
Hey boy, you better bring the chick around
To the sad, sad truth, the dirty lowdown

(Who, I wonder, wonder, wonder, wonder who)
Taught her how to talk like that
(Who, I wonder, wonder, wonder, wonder who)
Gave her that big idea

Nothing you can’t handle, nothing you ain’t got
Put your money on the table and drive it off the lot
Turn on that old lovelight and turn a maybe to a yes
Same old schoolboy game got you into this mess
Hey son, you better get back to town
Face the sad old truth, the dirty lowdown

Come on back down little son
Dig the low, low, low, low, lowdown

You ain’t got to be so bad, got to be so cold
This dog eat dog existence sure is getting old
Got to have a Jones for this, Jones for that
This running with the Joneses, boy, just ain’t where it’s at
You gonna come back around
To the sad, sad truth, the dirty lowdown

Writer(s): David Paich, William Scaggs