I think the fact that Damon didn’t own up to meeting her first is more of the deciding factor. All the times Elena said, “I met Stefan first”, “I owe it to him”, and every other excuse and here was Damon with the fact that he met her first and already knew everything she needed, wanted. That’s the deciding factor. The fact that Damon wanted her to pick him because she can’t stand another second without him. He wants to be chosen for the right reasons. The deciding factor is Damon’s selflessness.
(Source: mysticonfessions, via drinkswithdamon)