Everyone has a line drawn in the sand - of what they find tasteful or distasteful. Some peoples lines are nearer to the "puritan" zone than others, and as long as they are simply getting offended, and not legislating against it, that's their prerogative.

While offence is indeed taken rather than given, the provocateur should understand that there may be social consequences for crossing peoples lines. Being entitled to do something is not necessarily enough of a good reason to do something. I may be entitled to attend a funeral wearing nothing but a thong, but by most reasonable definitions, that would be a dick move, and let's face it, a pretty "cheap" way to get attention.

So in my opinion, you should use whatever language or imagery as you see fit, but don't expect it to be to everyones tastes. I for one find spread-eagle women rather adorable. Dass-juss-mee-tho.