sometimes the actual mention of the things like rape games and what people percieve to be 'violence' etc can scare guys a little,ive known quite a few who've admitted they fantasise about it but also because of its connotations feel a bit torn and guilty about that.

as well as books do you have any mild bdsm type movies? wait til he's relaxed put your sexy lingerie on snuggle up and drop a few hints.

or take him shopping and try coaxing him to buy a 'bdsm beginners' type kit ,you know the sort a bit of soft rope, fluffy cuffs, collar etc from anne summers or some such place, thats more likely to come across to him as a little kinky saturday night fun!

and if he's up for it at some point hopefully he'll start to take a more active interest in it.

i really hope that whatever you do works out,ive been there myself and know how difficult and frustrating it can be ....good luck with it