So you haven't formed a legal entity for your start-up, meaning you don't have a operating agreement signed between you and your business partners? Did you sign any agreement(s) between you and your business partners like Non-disclosure agreements or confidentiality etc.?
Disclaimer: The information that I post in this forum is NOT legal advice and should not be relied as such. It is intended to provide general information in summary form on legal topics. Formal legal advice should be sought in particular matters.