Wife Says “It’s Either Me or His Mom”: Seeking Advice on Whether to Divorce

Relationships between exes can be strained, and having a common child and being in a new relationship can make it even more problematic. A user shared his family situation on Reddit, where he and his girlfriend refused to host his son for a weekend while his mom was going on a date, and wondered whether he was on the right.
I am a 55-year-old man in a relationship with a 40-year-old woman for the past 3 years. My ex-wife and I divorced 4.5 years ago, and she hasn’t quite moved on from it yet.
She left me for a coworker, and our relationship was tumultuous and toxic. However, after her new relationship failed, she started being more amicable towards me. I have a 15-year-old son named Sean, and we have a strong bond. His mother and I are working on co-parenting better.
The problem arises because my ex-wife is unhappy about my current relationship and the fact that she is struggling to maintain a romantic relationship of her own. She disapproves of my girlfriend, causing tension between my son, my girlfriend, and herself. Despite my efforts to talk to Sean, he seems to take after his mother’s behavior. My girlfriend, understandably, does not want to force a relationship with them if they are unwilling.
Recently, while I was out of town for work, my ex-wife asked if Sean could stay at my place while she spends the weekend with someone new. I declined, as my girlfriend is not comfortable watching over someone who has mistreated her. I believe that Sean is old enough to stay home alone at their house. My ex accuses me of prioritizing my girlfriend over our son, but I see it as teaching Sean the consequences of blindly following his mother’s actions.
My girlfriend also expressed discomfort with being alone with a teenager who has shown animosity towards her. She is supportive of my decision and doesn’t want to be put in an awkward position. Our weekends with Sean are scheduled differently, so this request was unexpected.
Most of the people in the comments supported the author and even questioned his claim about choosing his girlfriend over his ex-wife:
However, there were also those who questioned his parenting approach to his son and forgot that a 15-year-old is still a child and shouldn’t be caught in the middle of his parents’ issues:
In another related story, an ex-wife used manipulative tactics to make sure her ex-husband provided financial assistance to her and their kids. Read the full story here.