Honestly, he didn't intend it to be such a long kiss. He was going to work her up to that but when she puts her hands on his shoulders he stops considering breaking the kiss. Instead he slides the hand on her hip around to the small of her back. The hand holding his beer goes to rest against her shoulder and he's just holding the neck of the bottle with his forefinger and his thumb. He puts his other fingers against her cheek and sort of slides his hand back into her hair.