The love triangle between Elena, Stefan, and Damon was at the center of The Vampire Diaries during its early seasons, and it all began when Damon started falling in love with his brother's girlfriend. At first, Damon was seemingly only enthralled by Elena because she was Katherine Pierce's doppelgänger (the woman he had been in love with for more than a century). One season 1 episode changed everything for the vampire, though. Of course, Elena had feelings for Stefan at the show's beginning, but everything became more complicated once she met Damon and truly got to know him.

https://screenrant.com/vampire-diaries-episode-damon-love-elena-georgia-trip/