It would be foolishly presumptuous of me to try and give you any type of advice without first knowing more about you, your significant other and/or the type of relationship you have established/aspire to have with her. But hey, I'm an arrogant idiot so please don't feel badly about taking my advice because I hardly ever use it anyway.
You will never be truly happy in any type of relationship if you're unable to trust the object of your desire enough to openly express your deepest secrete desires and fears with her. If you ever care to have it all then it is usually necessary to risk it all. Having said that, it is not necessary, nor prudent, to risk it on a single knee-jerk-all-the-cards-on-the-table coming out type of admission. In other words, the next time you find yourself in an intimate situation with your significant other, I think it not best that you start out by stating: 'Honey, what would you think about dressing up in real slutty cloths and then beating the shit out of me until I submit to becoming your personal dildo that you can use to satisfy your deepest secret desires'? Take it from someone who has tried this approach more times than I care to remember. It will most likely freak out even the most open minded people.
The best way to get someone to come around to your way of thinking is to do so in a way that makes them think that it was their idea in the first place when the actually do. Rent a home movie that has a scene or two of men being physically dominated by women .... not a movie that has it's central theme about women dominating men ... find one that most closely demonstrates the type of activity that you would like to engage in with her. Then, while the scene plays out on the tube, or immediately after the scene, find a subtle way to let her know that it really turns you on. A subdued 'MMmmmmm' sound while slightly brushing your crotch with your hand will usually be enough to get her attention. The key here is to get her to initiate the conversation.
If the chub-rub turns out not to be enough then maybe try snuggling tightly up to her and begin to passionately kiss her behind the ear and on the side of the neck while forcefully grinding your erect chub up against any part of her body you can get it next to. What your looking for here is for her to inquire: 'Whats gotten into you all of a sudden'? Play dumb and say something like: 'I dunno ... for some reason it turned me on watching that chick kick that dudes ass. I don't know why, but for some reason it always has for as long as I can remember'.
I'll bet you big money right now that if you do what I suggest above that you'll be pleasantly surprised as to how she responds to your words and actions. She's either going to laugh at you and say something like 'You ain't right'!, or something like, 'I'll kick your ass if it will make you feel better'. Either way you win. But don't expect this little innuendo to immediately change your sex life significantly. Take it slow ... but never stop on the go.
If it turns out that she is too much of a prude, or too uncaring of you to participate in these types of activities well then just know and accept the fact that she is not your soul mate. Only then can you make any decisions as to whether or not you want to remain with somebody in the type of relationship that you are currently in. One that involves self denial and deceit.
Now go and be happy my son.