If you tell him that you like him he may take advantage of you e.g. he says he likes you then you two get together, get intimate etc. He gets laid and then as soon as he sees he has a chance with your friend he dumps you. So going out with him seems like a no-no, if he really liked you he would've told you. All I can say is that you can be a friend and set him up with your friend, it it works then good for them, at least your still friends. Alternatively just ignore what he said and carry on with life and find someone new to love.