They force you to accept different kinds of abuse from their family
Dealing with your in-laws can turn out to be a rather difficult job, and there might be many landmines already built into your relationship.
Of course, you have to show respect to your spouse’s relationship with his/her family, but this doesn’t mean that you have to take their insults, and let them ignore, hurt, or make fun of you (as long as they’re the only ones that are laughing).
Even more, your partner shouldn’t turn a blind eye to any of this, especially when it comes to disrespectful things that your friends and family might say to you. Your partner should stand as a guide on how your loved ones have to treat you, so if he/she lets them get away with treating you so poorly, you won’t stand a chance.
Also, if they ask you to “just let go”, then maybe you have to consider letting go to something else, too (if you know what I mean).