I think if they're a potential partner then you're still working out if they're trustworthy.
daing v. marriage
What kind of partner? Significant other, business partner, partner in crime(never trust this one) or?? Significant other whether potential or other if you don't trust isn't worth being involved with IMO. Same with friends, every thing else... use your own judgement
Everyone is a potential partner to begin with and they weren't trustworthy they wouldn't get so far as to be partner.