The circumstances.

If it wasn’t a situation where it was a recurring character trait thing, but one time, unusual circumstances, quickly disclosed, STD tested before we did it again, and if we’d been together a long time first.

Now, having said that - I don’t think infidelity comes out of nowhere, if it’s not a person who just always will cheat, there are usually problems leading to it. So it’s unlikely to work out. But I might be willing to see if it could.