Question: My brother-in-law, husband to my husband's sister, has been verbally abusing my husband for over a year (through e-mail to him and rants to other relatives). His sister will not intervene, since her husband has proceeded with her knowledge and approval.
The dilemma: We are often invited to family events that these two will surely attend. Our nonattendance is noted. So, how to handle these situations? Parents-in-law say not going would be "politically" loathsome (allowing bro-in-law and sis to "win"); ignoring bro-in-law seems childish; small-talk seems abhorrent — unless it's to call him out as the ass he is, which would be rude. Answer: It all adds up to a classic bullying scene. Talk to your husband about how you and he can handle this in a way less reminiscent of rolling onto your backs.
You can, for example, explain to his parents that skipping encounters with the brother- and sister-in-law is your right, and if the rest of the family misses you, then they can take it up with the brother.
If they don't like that (or you don't, or your husband doesn't), you can say you'll gladly take your place at family gatherings, but do so feeling no obligation to pretend all is peachy to maintain appearances. Perhaps: "Whenever you're ready to have a civilized conversation, BIL, I'm here. Until then, please understand I have nothing to say to you." Add a turkey and you have yourself a Thanksgiving.
If your husband refuses to rock the boat, remind him that everything he does or doesn't do at this point is a statement; it might as well state what he wants to say.