3. Baby Mama Drama
Early on in Glee's run, President of the Celibacy Club Quinn shockingly becomes pregnant by Puck—who she cheated on Finn with ("you got me drunk on wine coolers and I felt fat that day"). To avoid more scandal, she convinces Finn that the baby is his even though the two never actually hit the high notes together (he's not that bright, and was prone to early, um, overexcitement during hot tub makeout sessions).
Around the same time, Mr. Schuester's wife Terri finds out that she's also expecting. After discovering it was only a hysterical pregnancy, she pillow-under-the-shirts it in hopes that a baby on the way would save her strained marriage. Only, there would be no child coming—which is why she corners Quinn and tries to convince the teen to let her keep the baby after it's born. (That whole plan goes by the wayside when Will discovers that Terri was using as a fake stomach and leaves her.)
And even Glee's grown children endure baby mama drama. We learn that Rachel's two gay dads adopted her as a newborn, clearing the way for the perfect sweeps week plot: the return of her biological mom. Amping up the drama, her mother, Shelby, is also the director of New Directions' rival choir, Vocal Adrenaline. It only takes a few emotional duets between estranged mom and daughter to realize they can't pursue a relationship this late in life.
Yet on Glee, everything comes full circle. Quinn's season finale delivery ends with a twist: after her brief, eye-opening reconnection with Rachel, Shelby adopts Quinn's newborn, getting a second chance at raising a little girl.