If I was a celebrity, the first thing I'd think is that my privacy will constantly get invaded.
I would not post nude pics of myself over the phone. If a celebrity WERE to do such a thing, are they doing it with the phone that others know about? I would keep a separate phone just for my significant other if I wanted to get kinky. Going to a phone that my partner only uses for few/no other people. Less likely to get attention brought to it.
Even then, just be aware that you're going to get fucking hacked. ALWAYS keep that mentality. It's ignorant to think otherwise.