Blood is Thicker Than Watercolor

After a leader of the art world buys Marlon's paint-smeared dropcloth, Marlon turns into a temperamental artist, much to Shawn's disgust. But Marlon's artistic career hits a snag when Lou catches a vandal putting graffiti on Pops' diner: the art patrons become so impressed with the graffiti artist that they abandon Marlon.