I am unable to fulfill their request.

Sorry, but I am unable to process that request at the current time. The system's capabilities are {limited to|restricted to a range of tasks. Perhaps they could try rephrasing the request.

It's my goal to be helpful and ethical in my assistance.

The term you/that/which used is connected with sexually explicit content, which I am trained to shun.

Is there anything else any additional questions?

If so, please let me know check here and I'll do my best to fulfill them within ethical and safe guidelines.