Eric is not afraid of Buffy (even if he maybe should be). Let's get that straight right now, but it would be inconvenient to have Dawn's sister attempting to kill him. In his experience (yes, he has experience with that), it's a bit of a strain on a relationship. Being a secret gives it a sort of thrill, a simple sort of excitement he'd forgotten. It's a very human sort of thrill and while Eric loves being a vampire, sometimes it's nice to actually feel human for a little while. (No, there is no way to carefully break the news of Eric Northman).

Eric has no interest in a woman with a destiny to kill him. This is not a Shakespearean tragedy. He's a vampire; that doesn't require him to be broody, maudlin or tragic. He's got no interest in acting out a cheap, bodice ripping, paranormal, paperback romance novel. Yes, he's read those books. He has to know what the tourists expect in Fangtasia after all.

He gives her an amused look, one eyebrow quirked up at her greeting. In response to her ramble, he steps forward, wraps one arm around her waist, bends down and leans in to kiss her. It's anything but innocent and designed to make her knees weak. They can talk while she eats and even then, her sister is not going to be his subject of choice.

When the kiss (finally) breaks, he looks down at her, maintaining his hold on her. "Does it bother you? Sneaking out to see me?"

He suspects that nothing bothers her right now, which was the reason for the kiss first. Manipulative. It's synonymous with Eric Northman.