Confessions By Strangers #49: Cheating mom

Would you like to protect somebody you love? My confession is I recently went to visit my parents and walked in on my mom cuddling another guy in the hallway. After he left mom's explanation was that she liked a bit of mystery in her relationship. Upon pushing the issue further I found out she's been having an affair for the last 3 months. My parents both married in their twenties and have been married for 22 years. Doing the maths my mom met this guy shortly after my 19th birthday in October. She has asked me not to tell my dad but I can't help but feel betrayed. My dad works hard to give my mom everything she wants, he's always telling her how much he loves her and taking her out for dates etc.

As their only child I was doted upon by my dad, I can't help but think my mom must feel stupid if she thinks I would side with her if it came to it. My boyfriend thinks I should stay out of it but my mom made her bed when she brought me into it, I love my dad very much and this would devastate him, I want to tell him but I don't want to be the one to break it to him.