What's the best way to handle a situation where you are asked to keep a secret involving illegal activity?

The only ethical and legal course of action is to refuse to keep the secret and, depending on the severity and nature of the illegal activity, consider reporting it to the appropriate authorities. Being asked to conceal illegal activity puts you in a position of potential legal liability and compromises your integrity. Clearly and firmly state that you cannot be complicit in any illegal activities. Explain that your ethical and legal obligations prevent you from keeping such a secret. Document the request and the conversation in detail. Seek legal counsel to understand your rights and obligations. Depending on the circumstances, you may have a legal duty to report the activity to law enforcement or regulatory agencies. Protecting yourself and upholding the law are paramount, even if it means damaging a relationship. For example, if you are asked to conceal evidence of tax evasion, you should refuse and consult with a lawyer about whether you are obligated to report the activity to the tax authorities.