What can I do to my boyfriend that is so good he'll never forget it?

Sorry to say it but give him amazing sex - take control and make him feel really special.

maybe am not the right person to answer that question but let me tell you something my Ex used to come back to me every time just for that simple reason, SMILE .maybe it's very simple to be true but believe me he will always remember that every time you were next to him you were smiling that's the image he will always remember and that's the girl he will always run to. even if you had a bad day or a little fight try to end it up with a smile and trust me he will remember that face smiling at him forever.