Lemon began his career as theater critic for the Austin Chronicle.
His darkly comic debut stage work, Jesus Hates Me, received its world premiere by the Denver Center Theatre Company as part of the inaugural Colorado New Play Summit, Winter - 2006. The production sparked thousands of letters of protest from conservative Christian groups across the nation and was officially condemned by the Catholic Church.
Variety called the play "irreverent and at times as profane as rap, yet filled with pertinent issues and rebellious politics." Backstage called the play "an exquisite comedy, featuring dark black lines of intriguing thought, with some of the funniest lines ever to appear onstage" while The Denver Post called it "howlingly funny."
The Texas premiere was produced by Kitchen Dog Theater of Dallas in Fall - 2006. The Dallas Morning News' review stated, "exceptionally well acted, impressively physical and ultimately about something more than finding the laugh lines."
The play was a featured reading at the Steppenwolf Theatre Company, Horizon Theatre's 2006 New South PlayWorks Festival, the Hartford Stage's 2005 Brand:NEW Festival of Plays and the Alabama Shakespeare Festival's 2005 Southern Writer's Project. It was also chosen to be a part of the American National Theater's premiere fundraiser, chaired by Paul Newman, in New York, May - 2005.
In 2009 the West Coast Premiere of Jesus Hates Me was produced by the Chance Theater of Anaheim. The Los Angeles Times said of this production "Lemon's dramedy about the search for meaning may offend as often as it convulses but it is certainly vivid. Lemon's narrative is both wildly inappropriate and keenly idiomatic." The Orange County Register said "Lemon is a keen observer of human flaws and frailties. Lemon skillfully merges dozens of minute details to form a seriocomic mosaic."
South Coast Repertory Theater of Costa Mesa hosted the Chance Theater's production, Winter - 2010. The production launched Studio SCR spotlighting the cutting edge works of America's most controversial playwrights. Other regional productions include the American Repertory Theater of West New York (Buffalo), Paper Wing Theatre (Monterey) and Ion Theatre (San Diego).
Lemon has served as playwright in residence at theaters across America and has been a lecturer at the University of Michigan, The University of Georgia, Washington University and The University of Texas.