More or less Kol was just surprised. He hadn't been expecting anyone and without those Vampire senses he hadn't known who was on the other side of the door. The hearing was something he missed. That was more because he heard a lot more than he did in this body.
It wasn't that he didn't want to see her… he had just been preoccupied. Since Kol turned up here he had been focused on one single thing. Finding the items and things he would need to protect himself against his brother if he needed it. It didn't matter that people swore that Nik was much different here. Much different than the person they all knew. He spent too many years daggered, laying inside a box at the hands of his brother. He knew exactly the kind of person Niklaus was and will always be.
Before he could say anything else she was coming towards him. And just like that she was pressing her lips to his. Kol gave into the kiss before eventually pulling back.