It’s perfectly reasonable to say something like “after working together for a few months we determined that we didn’t really ‘click’ as a founding team and deci

It’s perfectly reasonable to say something like “after working together for a few months we determined that we didn’t really ‘click’ as a founding team and decided to go our separate ways.” That’s something that happens all the time, and you won’t be judged for it by any reasonably astute observer - especially for a project that only lasted a few months. Depending on how far along you got on the project, another business savvy answer might be that the proof of concept provided the information you needed to determine that the business wasn’t going to be viable (or wasn’t going to be able to produce the returns you were hoping for), so you agreed not to invest further in a losing proposition.