I posted this on the main site, but I think it's a good fit for being posted here, too.

As many of you know, I've been a SD for 25 years.

I've certainly had my fair share of issues to contend with regarding my own stepmother. These include her angry outbursts towards others (I seemed to be a favorite target of hers), her attempt to PAS me against my mom, and her gossiping and saying other mean things about me when she knew I could hear her.
I don't see her a lot. My dad and I have worked out a lot of issues through counseling. I invited my stepmother to come to counseling with me as well. She chose not to. Her choice. My dad and I have greatly benefitted from our counseling sessions together. We, with the help of my therapist, managed to find ways to reduce the drama and create a close relationship.

I called him a few days ago to say hi. I could hear my stepmother screaming about something in the background about how "the f*cking tv doesn't work" and being critical of him for not fixing it sooner. This is a guy who owns a construction company and works from 6 am-11 pm every day excepting Sundays.
I felt feelings of anger towards her right then. Nobody wants to hear their dad get yelled at like that. Instead I channeled that energy towards our conversation about politics, which we both follow studiously. I reminded myself that my dad is a big boy who can fight his own battles. I know that if I were with someone like my stepmother he'd rip them a new one for treating me like that. However, I think that's part of being a parent.

These sorts of behaviors and actions on my stepmother's part greatly contributed to my anger towards her. However, carrying around so much hate wore me out emotionally. I attribute my treating her nicely at all times, even when I loathed her, to my dad's insistence that I do so. I feel his insisting upon it forced me to take a look at my issues and feelings and try to work them out.
I have accepted the fact that my stepmother will, to some extent, always be in my life. I've managed to find ways to minimize the drama so that when it comes up I can deal with it rationally.

I wish I could email all the bitter adult SDs out there who hold a grudge towards SM and act like she's the root of all their problems. Being weighted down by hate isn't worth it. I had to remind myself of that this week. There's a passage in the Biblical boom of Sirach about hate. Those who choose to keep hating never heal or find peace. Nobody's saying SMs and SDs have to love or like each other, or even give two $hits about each other, but if you love your dad, get yourself professional help and be nice to SM. Learn to let go of the hate in healthy ways. Invite your dad to counseling, and consider making a few appointments for you and SM too. Dropping the hate won't happen overnight and might be an arduous process, but you'll feel so much happier because of it. I did, and I feel great.

***Add*** here's the quote from Sirach and the Bible: Wrath and anger are hateful things,
yet the sinner hugs them tight.
The vengeful will suffer the LORD’s vengeance,
for he remembers their sins in detail.
Forgive your neighbor’s injustice;
then when you pray, your own sins will be forgiven.
Could anyone nourish anger against another
and expect healing from the LORD?
Could anyone refuse mercy to another like himself,
can he seek pardon for his own sins?
If one who is but flesh cherishes wrath,
who will forgive his sins?
Remember your last days, set enmity aside;
remember death and decay, and cease from sin!
Think of the commandments, hate not your neighbor;
remember the Most High’s covenant, and overlook faults. (Sirach 27:30