We're not being rude, I think you are taking offense too easily. It takes a lot of skill and knowledge to be a good dance teacher.
How did you learn to dance? Did a friend or relative just show you the steps, or did you go take lessons with experienced teachers?
If this is just a case of friends showing friends how to dance, then do what you think is comfortable for both of you. But if you are an actual dance teacher, who has been trained in how to teach effectively, then your training should have included information that would have answered your question. If it didn't include that, then your teacher training was rather lacking.
Now, to actually answer your question: partner dance teachers who go through actual teacher training courses and take the teacher examinations from the various teaching societies (like the ISTD, ITDA, Terpsichore Society, or DVIDA) have to understand and be able to demonstrate, dance, and teach both the man's and lady's part. That way, any person can teach any other person about dancing, regardless of what gender the teacher and the student are. Since you didn't know or realize that, it indicates that you don't really know all that much about teaching dancing at this point. Are you sure you are really ready to teach, and to be a good teacher? Maybe you could be a great teacher if you took the time to get some more information and training.