AITA for refusing to help my ex-wife financially after she cheated on me?

I (35M) was married to my ex-wife (34F) for ten years. We built a life together, and I thought we were happy until I discovered she was having an affair. It shattered me, and the divorce process was grueling. I had to start over from scratch, emotionally and financially.

Despite everything, I remained committed to supporting our two children. I provide generous child support and ensure they have everything they need. Recently, my ex reached out to me, saying she’s in a tight spot financially and asked if I could lend her some money to cover her expenses.

I declined, explaining that my responsibility is to our children, not to her. She argued that helping her would ultimately benefit the kids, but I stood firm. I’ve already endured enough pain and can’t see myself extending help to someone who betrayed my trust so deeply.

Now, she’s turned some of our mutual friends against me, saying I’m being vindictive and punishing her through financial means. They believe I should help her for the sake of our children, but I can’t bring myself to do it. AITA?