Klaus is talking to Rebekah, telling her about Bonnie and how she is always on his mind . The rest is pretty much Klaus giving Bonnie an ultimatum 'choose me or your fire, be mine or you will burn'.
If you've seen the film Savages then this is the VD version of it with Bonnie as the main character. If you haven't seen it then you get the gist of it and it's a pretty amazing video :)
