Final answer:
When encountering residents in a sexual encounter, report the incident to a supervisor while maintaining resident dignity and privacy.
Step-by-step explanation:
If encountering residents having a sexual encounter in a professional setting such as caregiving or healthcare, the appropriate action would be to report the incident to the supervisor or the appropriate authority. It is critical to maintain professionalism and respect the privacy of the residents, so ignoring the situation or discussing it with others for gossip would not be appropriate.
Additionally, joining in the activity is completely out of the question as it violates professional boundaries and ethical standards. When reporting, it's important to do so in a way that is sensitive to the residents' dignity and privacy.