I had my picture done like this a few years ago- not for a bf but just for myself since i sort of had this feeling that it would never get any better ( at that age- I think I was 28 then). I started by looking at pin-up girl pictures to get ideas of "risque" poses and then just went from there. The girl who took the pics was using them for a photography class and I drank a glass of wine beforehand to help me relax.
Have fun with it- often the things that you think won't look that great turn out the most interesting so be creative! You could even be brave and post some when you are done.