She might not be too keen on the idea at first, but maybe ask her if you can post some erotic-but-not-revealing ( i.e. not nekkid ) pics, sexy poses, that kind of thing. The reaction from posters here might just convince her to let you post more...don't know too many women who don't enjoy being appreciated for their physical attributes, she might find it a real turn-on, and you might end up having a lit posting addict on your hands!
Or she might not dig on it....ask her, show her respect and understanding in the matter, be subtle and take it slow and Ya can't go wrong.
Just my $.02 on the subject, your milage may vary...