Totally get this, as my family and my wife don't get along at "all". So in the past I would try to talk to them about my issues with her, and little did I realize they were doing happy dances and were hoping for a breakup and later a divorce.
So we never had kids, take the spin that a man isn't a man unless he has kids. Last year, my sister on traumabook when into a tirade, and something snapped in me. It was part understanding I deserved better, part therapy, and part meeting a friend who gave a shit.
I had a fun explosion pre-visit where I went off on how they made me feel for decades at the holidays. It was a massive turn, and in turn it wasn't easy, since I got to see the usual anti-patterns of look at what you are doing to "us".
So I feel ya, and knowing you enjoy sex, enjoy pleasing people in the fine arts of intimacy and pleasure can warp the minds of those where intimacy is only surrounded by the coat of couples privilege.
Are they wrong? No their beliefs are fine as long as they don't shame and blame and imprint on others.
It sucks your non-biological mother is holding your biological father hostage. Of course he is his own man, but you are right on the emotional scraps.
So a silver lining for me this year was COVID, since I could complete my healing process sans holiday, which is critical.
So 2020 had a lot of positives wrapped in a nasty evil, the key is finding them.
I have seen your writing and of course commented on it, but after reading this, I have to say you must really excel at what you do.
So claps and hugs (consensual and platonic) to you for being an awesome human being!