1. Put in some ear buds and listen to music when the in laws come to visit. If all they want to do is fight, they will have to find someone that can hear them.
2.A controlling in law is controlled by not letting them know everything nor answering their every answer.
3. Do not reply to every question in emails or phone texts.
4. Continue on with your life - smile and ROCK ON with your music.
*** This has worked for my 32 years of in-laws thus far!