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 atau your fire, be mine atau anda will burn'.
If you've seen the film Savages then this is the VD version of it with Bonnie as the main character. If anda haven't seen it then anda get the gist of it and it's a pretty amazing video :)