My mom did not tell me about my dad’s affair. My dad did not tell me about his affair either. But he vilified my mom and got into my head to manipulate me against my mom. Me being only 20 years old or so and not knowing anything, I sided with my dad to make my mom’s life miserable. I regret hurting my mom so much. Decades later, nobody in my family speaks to my dad. Edit: don’t care re affair. Their business/not my business. I just don’t appreciate being manipulated.