'Smash': Ivy and Dev (Season 1, Episode 13)
By the time Broadway ensemble veteran Ivy slept with rival Karen Cartwright's boyfriend, the only thing shocking about this hookup was that it didn't happen sooner. Ivy had spent the entire season trying to trip up the fresh-faced ingenue as they vied for the part of Marilyn Monroe in Smash's show-within-a-show, Bombshell. So when she bumped into a heartbroken Dev at a bar, drowning their sorrows in booze and each other seemed intuitive: Karen had waffled at Dev's proposal, while Ivy had learned her on-again, off-again boyfriend was banging Uma Thurman. But Ivy's one-night stand with Dev wound up being the best thing that ever happened to Karen. Once the Iowa transplant learned the truth, she grew a pair and kicked Douchey Dev to the curb. Permanently: He's not returning for Season Two.