Disgusted and heartbroken

Yesterday I saw my partner/baby's dad spit at two Indian women on the street. I was completely shocked, disgusted, furious. He didn't realise I had seen him do it and I went off at him and we had a huge argument about it and haven't spoken since. I'm so fucking confused and upset. I've been with him for 12 years and did not think he was this kind of person?! I feel like I don't know who he actually is. I don't think I want to be with him anymore. I feel differently about him but I'm just so confused by this. I can't imagine our life without him but I keep questioning who he even is anymore and if I even really know him?! I don't know what to do.