Emmy Award-winning actor Sean Hayes is booked to guest star in a multi-episode arc on the Broadway-themed drama series \"Smash,\" NBC said Monday. The gig will reunite Hayes with his former \"Will & Grace\" cast member, \"Smash\" regular Debra Messing. Hayes will play Terrence Falls, a comedic television and film star making his Broadway debut in the musical \"Liaisons,\" based on the novel \"Les Liaisons Dangereuses.\" \"Due to a series of comic circumstances, he becomes a major thorn in the side for Ivy Lynn -- [played by Megan Hilty] and other characters,\" a synopsis said.