Buffy the Vampire Slayer had only one Christmas episode, but it went a long way to explaining a couple of big things.

Thanks to streaming, viewers can now bingewatch 'Buffy the Vampire Slayer' and spot all the small details that were missed the first time.

Some TV couples make us swoon, while others break our hearts. But every so often a love story comes along that does both—and becomes a major part of pop culture history. That’s exactly what happened ...