Stefan and Elena had always pictured their life together as being an inseparable couple and having a love that was much more stronger than any immortal who crossed their way, and there were plenty of them.
For one, there was the beautiful unstoppable Katherina Petrova, an authentic mirror image of Elena. Katherina mostly known as Katherine Pierce, was an old eternal love for Stefan and Damon Salvatore, both brothers who fought to receive the glorious love of the beautiful Katherina. One who had used them and abandoned them, for her own purposes leaving both brothers torn and heartbroken not to mention supernatural Vampires.
Then Damon Salvatore, another beautiful immortal who opposed of Stefan and Elena's relationship, mostly because of the heart shaking feelings Damon contained for Elena, which Elena unwillingly had to admit to feeling the same things for Damon, even though she didn't admit it to Stefan, Elena had strong feelings for the glorious, heartbreaking Damon Salvatore. Which she didn't dare to admit, fearing the strong emotions she contained for Damon, as she believed those feelings to be wrong and impossible. Elena didn't even have to spell it out for Stefan, he already knew about the secret feelings Elena hid, even though they weren't as secret as she swore them to be.
Then there were the rest. Plenty of people trying to get into the middle of the relationship Elena and Stefan contained, but not as strongly and vicious as Katherina and Damon, they were the most dangerous immortals for Elena. At least sentimentally they were. The rest she could control, but when it came to Katherine and Damon, Elena never knew what to expect even though Stefan always seemed to have a cleared idea of what both paranoic immortals would do next.