When You Really Don't Like Your In-Laws
This can either be a huge problem, because your spouse is very, very close to his or her family and you just can't stand them, or a really huge problem because your in-laws are genuinely awful people and both of you would rather have root canal without anesthesia than sit in the same room with them for more than five minutes.
I'm going to assume, for the sake of this hub, that you've given yourself enough time to honestly get to know your in-laws, and that you've given them enough real chances to prove to you that they really aren't the jerks you originally took them for - and you still don't like them.
First of all, even if you have the only grandchildren, there's no law that says you have to like the people your husband and wife also call "family." Lucky for you. However, for the sake of your relationship with your spouse, you do at least need to be polite to them. This may be hard if they live nearby and seem to want the two of you over every weekend for some reason or other. However, there are strategies you can employ. You can try very hard to always have a "project" to help them with when you visit. Offer to clean the gutters, or mow the lawn, or weed the garden. Chances are, they'll not only leave you alone with your onerous task, because God forbid you ask them to pitch in, they'll even think better of you for your labors on their behalf.
If chores are out of the question, find a family activity to distract them. My mother visited recently, and since neither my husband Alex nor I like her very much, mostly due to her constant stream of advice and/or cutting comments, I offered to go see the movie Harry Potter and the Order of the Phoenix with her. She is a Harry Potter fan, I am a Harry Potter fan. My father is not, and Alex isn't particularly either, so this was the only way either of us was going to get to see the film in the theater. Three hours of together time with my mother that prohibited talking! It doesn't get any more win-win than that!
If your spouse is really close to his or her family, and you just can't stand them, you might want to seriously consider keeping the bulk of your opinion to yourself, for the sake of your relationship. Make sure your partner knows how you feel, then drop it. If your in-laws live nearby and you can't always manage to fill the visit with chores or distracting family activities, stay nice. In fact, if your in-laws know how you feel about them - and they probably do - it will really piss them off if you're acting more civilized and more polite than they are! Plus, your spouse will love you for it. Take what they dish out during the visit, but wait to vent until you get home - or until they go home. And your venting doesn't need to be verbal. In fact, it's probably more effective if it's not. Make a loaf of bread and pretend the dough you're vigorously kneading is your brother-in-law's head. Get out the weed whacker and project your mother-in-law's face onto every weed you cut down.
Unfortunately, when you marry your husband or wife, on some level you marry their entire family - for better or for worse. This little bit of knowledge alone is what kept me from acting on my true feelings for Alex for years. The thought of being his mother's daughter-in-law was more than a little romantically prohibitive! She is a formidable, opinionated woman, born and raised in Germany during World War II, and she does not suffer idiots gracefully. But, over time I learned that the fact that I really love her son (the last of her seven children to marry), earned me a lot of esteem in her eyes.
And when I produced a daughter that is the spitting image of her Oma and then started asking my mother-in-law for parenting advice from time to time, well, let's just say that at this point I am on her list of "favored in-laws". I may not like the woman much, but I sure like being on her good side!