My best guess is you can’t just take your son to italy without you ex’s ok. It sounds like your son is a Canadian. Find out what the rules are and follow them. I live in CA in USA and you would have 50/50 custody and probably end up paying child support. Find out the laws in Canada where you live. I am so sorry this sounds difficult. My best to you and your little boy. Your son will have strong male roll models in his life without his father. Biology isn’t necessarily that important.