You have to be honest and direct. You have to take the risk If you want the rewards (for you thats BSdam stuff). You may have to explain how you see your roles playing out, who is dom and whos sub etc. You should not be ashamed of your fetish, lots of peoole have them and its more common than you think.
Tell him you want to start slow and introduce things here and there. Hopefully he can give it a try fo you. You need to open the door for him to share his fantasies too so you can explore what turns you both on.
Tell your husband you want to have a serious discussion during which time the two of you share your thoughts and feelings about your Needs, Wants, and Fears. Give him time to prepare -- then be prepared to be shocked by your husband. I can almost guarantee you that your husband has been hiding his wants and fantasies from you, just as you have been hiding yours from him -- and for the same reasons.
If you both go into the discussion with open minds and a willingness to negotiate and compromise, you will learn that there are things you want that he is willing to trade you for things he wants. The trick is in negotiating arrangements that are a win-win for you both. Needs are those things that you absolutely must have to achieve happiness and fulfillment. These are typically things like a place to live, a roof over your head, and food to eat. Wants are things that you want that can range from being almost a need to things that may have been a passing thought. Fears are things that you fear. For example, for may guys, any homosexual contact is a fear, and certainly loss of your needs are fears.
If you are afraid you are "alone" in your bdsm wants, spend some time reading experiences here in EP. You will find that there are many people who share your interests and wants. Your husband has wants of his own, some of which will shock you. But if he loves you, you do not need to fear rejection -- at worst, you probably need to fear that he will reject your wants and be unwilling or unable to negotiate a fair exchange with you. I would be surprised if this happens.
If you are too afraid to jump right into this, consider purchasing copies of a few magazines like Penthouse Forum and Penthouse Variations. These monthly mags have stories written by letter writers from people with a wide range of interests. Take turns picking stories that interest each of you and reading the stories to one another, then talking about how they stories make you feel. There are also some neat board games you can buy ad nicer Adult stores or on the internet where they have cards or some other device that each of you take turns with that suggest actions to take or things to do -- kind of like formalized Truth or Dare. These can help you both better understand each others fantasies, wants, and boundaries -- what you are willing to try and what not.
Best of luck to you. Your BDSM fantasies are not at all unusual, are a fairly common fantasy of many women and men, and not so out there that your husband is likely to react very unfavorably.
Just tell him you want him to spank you, tie you up, **** you like there's no tomorrow, pull your hair, whatever. Or first tell him you fantasize about those things. (I read one woman got her first ****** when her partner tied her up.) Show him this article. http://www.dailycal.org/article/104513/cavemen_do_it_better
Even the women at Berkley (of all places!) want to be manhandled in the bedroom. Here's another article with comments. http://www.femaleorgasmrevealed.com/femaleorgasm/the-game-of-domination/
If you read I Love Rough Sex group on EP it's mostly women expressing their cravings. You can amass a lot of evidence from this website that your hankerings are very mainstream.
I just went through this myself and the out come has been great so far. I brought it up one night while my husband an I were at a **** shop getting me a new outfit. I said " Lets look around before we go" as soon as we got to the kink/bdsm area I pointed to a tie-up kit and said. " Thats kind of hot" just to feel him out. His reply was" yeah I guess but I dont like any pain, thats a turn off" to which I replied " Thats ok cuz I wasnt thinking about it for you" he asked if i liked that kind of thing and all I said was " yeah i think its hot"
It took a few weeks and him breaking into the **** on my phn but next thing I knew it was on. Now our sex is something Kink.com would love to stream online. So good luck and hope this helps anyone in same situation.