This is most definitely a question for your attorney who will be responsible for helping you. Many factors. Family law is very fact intensive, and not really a good subject to try to discuss on the internet.
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The proper legal phrase in Florida is "substantial change of circumstances," though many lawyers and judges use the more precise phrase, "unanticipated, material, substantial change of circumstances." I'm not sure that there is any real difference between the words "substantial" and "material" in this context, but anyway, the phrase defines the standard needed for a judge to change a court-ordered timeshare in Florida. What constitutes a "substantial change of circumstances," is complex, and many judges and lawyers even disagree, but none of the things you've described would qualify--even added together--to be a "substantial change of circumstances."
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It should have been anticipated by both parties that either could start another relationship after the separation. Anticipated changes are not unexpected. That being said, the Court has wide discretion in deciding what amounts to a sufficient change. An experienced family law attorney would be able to help you navigate the factors.
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