They’re likely to be full of stories about their lives either today or in years gone by.  Let them tell their tales and make yourself a rapt audience of one.  You might learn something interesting, and it will make them feel good be listened to as well.  Many of the stories might be about your partner, and you might learn more about them in the process. Encourage your in-laws to communicate with you.  Invite them to “Tell me about life when you were growing up,” for instance. Families often fight about politics, religion, or the proper course to take in current events.  Don’t try to change someone set in their ways.  Similarly, don’t try to correct someone’s social habits.  If they spit, curse, or pick their nose in public, don’t feel obligated to call them out on it.  Your in-laws are likely to be quite a bit older than you, and people tend to be less receptive to new ideas and invitations to change when they reach seniority.  Respect their decisions and perspectives, even if you don’t agree with them. Try not to find fault with them.  Do not create a long list of grudges that you regularly churn out when complaining to others or yourself about your in-laws.  If your litany of issues becomes unmanageable, perhaps you should consider talking them through with your partner, and then, if necessary, with your in-laws directly. Treat your brother-in-law and sister-in-law as you would your own siblings.  Be friendly, cordial, and natural around them.  Be honest and open in your communication.  Relax when you are with them.  Don’t feel as if you’re being tested or studied by them.  Share with them your innermost feelings and thoughts, if appropriate.  After all, your in-laws are family.  Seeing them as such will go a long way toward helping you get along with them. They will always take their child’s or sibling’s side, and letting them know about problems on the home front will only make them worry.  Nobody wants to hear denigrating tales about their own son or daughter; hearing such things will likely make them...

TL;DR in Vietnamese:
Lắng nghe cha mẹ vợ/chồng bạn. Không nên tranh cãi vô ích. Đối xử với cha mẹ chồng/vợ của bạn tương tự như đối với cha/mẹ bạn. Không chia sẻ với họ về vấn đề mà bạn đang gặp phải với vợ/chồng bạn.