I think the advice of telling his family to "shut the F* up" isn't really practical advice. Most people (including ppl above) won't walk up to inlaws and just blurt out the phrase "Shut the F* up" . Even if that is what we would LIKE to say. I think you need a handfull of GREAT comments and GREAT comebacks up your sleeve. Different assertive comments for different things they may say to you (or your husband). For example below...
Them: "Would you like us to slip you some meat when she's not looking?"
You or Husband say: "Nah, we prefer not to get cancer, heart disease or diabetes. But you go ahead!"
Other great comments:
"So, you actually like torturing, exploiting and killing animals & our planet." (No matter what they say after this, you can just keep saying that over and over and over again.)
"Yes, you do contribute to the suffering, because...You buy, they die."
"Until you watch EATHLINGS, COWSPIRACY, WHAT THE HEALTH, (add dozens more) Then I don;t want to hear your uneducated opinion."
"Eating meat isn't necessary. It's actually detrimental to your health."
"I can show you a long list of Olympic and medal winning athletes who are 100% vegan, and in much better shape than you." (This list in on the internet)
"You are just normalizing violence."
"You obviously don't care about other innocent living beings at all, and you obviously don't care about our planet."
"You obviously have done ZERO research on the matter. So, until you do, I would stop talking."
"Vegans have 15% lower mortality rate, 78% lower rates in diabetes, 15% lower rate of cancer, and live longer than meat eaters. So, who is the smart eater, hummmm??"
"If you knew what was in your meat, you would never eat it."
"Your ignorance is going to kill you."
"Processed meat is legally classified as a GROUP 1 carcinogen. Same level as asbestos and plutonium."
"Red meat is classified as a GROUP 2 carcinogen."
"9 of the top 10 killers in America are preventable with diet. So many people die from these diseases because they have no clue about what food is good for them and what food is killing them, I suggest you educate yourself so you don't become another statistic."
"The food industry is lying to you, and they hope that you don't educate yourself, so they can make money from you buying the poison, and then make money from the cure to that poison."
"You obviously know nothing about diet, health, or veganism."
"Nothing tastes as good as healthy feels!!"
"I don't need to 'respect' anything anyone does that tortures other living beings and destroys our planet."
"Your 'choice' had an innocent victim."
"So please explain why you despise someone so much who actually cares about saving the lives of animals and saving our planet and taking care of their health? WHY does that bother you so much?"
"Deep down you know it's wrong, but you refuse to admit it."
"One day, hopefully before it's too late, you will realize we are right and you are wrong." (All it takes is a little research to find this out.)
"Since when was activism done silently?" (If you are an activist and they criticize that.)
"Oh, excuse me for actually caring about my health, caring about animals, and actually being one of the few people that cares about our planet."
"Shame on YOU for eating animals. You should be ashamed to STILL be eating animals in this day and age of information."
"Having a dead animal rotting inside your body is bad karma."
"We are natural herbivores. Look up the anatomy on an herbivore, omnivore, frugivore, and carnivore... Humans are the LEAST like a natural carnivore. Look it up!"
"You can't say you love animals, and then torture, exploit and kill them when you don't have to."
"There is no GOOD excuse to eat animals... plenty of bad excuses, but no good excuses."
Also, there are several GREAT arguments you can use in your favor from the book called "Eat Like You Care". It's not a long book, and it covers every single thing most meat eaters say to Vegans, and how you can reply to them. I am sure there are also good articles on this on the web. I also have a youtube channel that narrates this book mentioned, if you prefer to listen to it in your car while you drive. I also have a video that explains the difference between Herbivore vs Carnivore. Hope that helps!!!
PS - I agree that your husband should say something that makes them feel too uncomfortable or too bad for continuing their behavior, such as "If you guys don't respect out cruetly free & healthy eating lifestyle, then we will have no choice but to stop visiting you." THAT will probably make them stop.