Employee pretends to be friendly with coworker for months only to extract important information about the workplace: ‘The friendship part might have been real at first, but somewhere along the way it started feeling more like a project to him’ – FAIL Blog

Of course, I think our friend now has to start giving the workplace detective false, misleading information to cause erratic behaviour. I would advise saying things that don’t compromise the other person’s position, so we can keep it funny and less dramatic, but I would go full-force into performance mode. She could also let the other coworker who’s about to be used know what’s coming to them and plan a strategy against it. The key is always confusing the enemy. Ideally, he will get to such confusion that he’ll have to start asking direct questions and will stop seeming so friendly. Either way, an attitude like this won’t get you very far in life. People sooner or later realize you are fake, and you will end up alone, with fewer opportunities than the ones you’d have if you had been adorable and hardworking.