Thanks for your kind words R1Geezer - I assume no irony intended? Even if there is, I missed it on purpose because I take all compliments at face value!
So - to the question -
I think for the man it is entirely an individual matter of perception. One man may feel proud that the world looks at his partner and lusts after her, and another, and this seems to be Ronaldo - may feel that he is not comfortable with the situation.
I don't think Ronaldo is 'brave' to publish his feelings, it is really a matter for the two of them.
From experience - I dated a stripper years ago - you can get used to a woman's physical attraction, no matter how devastatingly attractive she is, and if there is nothing else to build your relationship, then it's going nowhere.
I would have no problem dating a woman who is photographed nude - if she is with me, then she is with me, and just because she shows her body does not mean it is open season for every guy with a penis and a pulse to step up and try it on - i think it is insulting to a woman in that situation to assume that nudity equals promiscuity.
Trust me, most men are far too shy to try and chat up a woman whose beautifukl body they have seen via her employment - and if you can;t trust your partner without 'keeping an eye on her', then she is ther wrong woman for you.
It would have been more gallant of Ronaldo to discuss this isue with his partner, and part company if he felt he could not resolve his feelings. To bleat everything to a newspaper simply makes her look bad, and makes himself look like a wuss - so no-one wins.