Carrie Brownstein is one of the founding members of the critically acclaimed band, Sleater-Kinney, she has also appeared on shows such as Portlandia and Transparent.
Means Heroin and is also a famous song by Guns N Roses on their debut album "Appetite for Destruction". When they are saying "Dancing with Mr. Brownstone" it means they are "Shootin Heroin"
"We Been Dancin' with Mr. Brownstone He's been knockin he won't leave me alone"