Family drama that I don't want to talk about because it creates too much drama

My sister got married a few months ago, whom I am very close with, or used to be. Things have changed between us, and I've told her such. I feel as though her husband's family is the matriarch of their family, and they plan absolutely everything around them. I feel her husband doesn't like my family very much, as evidence by, when my and my sister sit on a couch, he ALWAYS has to sit between us, and his reasoning is "I just like to make you mad". He's made my father look stupid, because he did not go to college, though he was very successful even without a diploma. But because I opened my mouth, about how I feel, that is pushed aside and left alone, I "created drama", in my fathers words. So I am done talking to people who know of this situation. I have come on here to let out a very large amount of pent up frustration, and quietly vent to people who don't know me, so that way I don't fall into insanity by anger.... Thank you for letting me rant