Elena... [And that's where the lecture dies on his lips. You know, the one about how sometimes we want the things we shouldn't want. Need them. The lecture the stems very directly from having been with a certain demon named Ruby and accidentally starting the apocalypse because of it.
But he doesn't know Damon that well. He trusts his instincts and his instincts say the guy is bad news, but he has no proof to offer. Nothing he can be secure in. If he says anything right now he's just the guy who didn't quite have time to be a real ex.
So...maybe he should get some proof.]
If you are ever in any kind of trouble, I want you to call me. [For now he'll do this, as awkward as it feels. It isn't like he's about to head out on the open road for parts and cases unknown. He'll still be here, doing what he does and she'll be...just out of reach.]