"Witchcraft is all about sex and nudity."

FALSE.

Witchcraft is an ancient fertility religion. However, it is common to confuse fertility and sex. Fertility is not just about having babies. It is about the fertility of the land and about inspiration, having new ideas.
Witchcraft is also a nature religion, having a high regard for nature and the ways in which it affects us. It is common to mistake the term 'nature religion' for 'naturist'. Naturists are those who prefer to remove their clothes as much of the time as possible, as they find it more natural and more comfortable.
There is nothing in the Craft which demands nudity. No one should ever be forced to do anything they are uncomfortable with.