Teasing my brother and feeling shame and guilt about it

This whole thing has been going on for a very long time. I am now an adult woman (29 y) with a "normal" sex life with a boyfriend my own age (I have always had a very strong libido and aside from liking sex really hard and forceful there is not really anything I like which isn't vanilla, really) and for the most part I can ignore it but left to my own devices (and admittedly during sex too as a private fantasy) I have very strong sexual fantasies mixed with extreme shame and guilt, although not at the same time. When I'm horny (for lack of a better word) I feel no guilt or shame, and I don't mean just masturbation, I can be in a horny "haze" for days when I'm in an almost constant state of arousal. But at other times I feel guilt and shame for what I have done (and still do to some extent, but for some reason I "know" that I should feel shame and regret about these acts too, but don't really) but that is always unconnected (temporally I mean) to my sexual fantasie "binges". 

When I was nine and my brother was 13 I was sitting across from him with my feet up and legs apart wearing a skirt. I noticed him looking at my crotch and I could see his penis get hard. I got super exited and spread my legs further apart and then closed them. I knew he was ashamed. I asked him to get up and get me a soda but I knew he couldn't because then his erect penis would show. I smiled and spread my legs wide apart and asked him; why can't you do that, is something wrong? Then I got a call and left him but I couldn't stop thinking about the whole thing. The next day my dad, mum, me and my brother were drinking juice and eating cookies in our backyard. I desperately wanted to tease him again, mum and dad being there just made it even more exiting, so I went up to my room, ostensibly to change into a bathing suit, and took of my underwear and went back down wearing just a long t-shirt. I squeezed in between mum and dad so my brother was sitting across from us and I was giggling and acting "cute innocent silly girl" with mum and dad while simultaneously spreading my legs just a little this time letting him see my pussy. He was totally confused, blushing hard, trying to hide his hard penis, trying not to look between my legs. Eventually my parents went inside to make coffee and then I spread my legs wide and looked him straight in the eye, smiling and saying "are you alright, you look a bit sick, maybe I should ask mom or dad to come back and check that you are ok". His penis had forced itself out of his swimming trunks and he was trying to cover it with a towel but still he could not keep his eyes of my pussy. And that was it for me. I had never ever been so exited in my life. I hadn't really begun having sexual feelings yet, and didn't recognize this huge wave of lust that came over me but it felt like I guess your first shot of  heroin feels or something, I was completely and utterly hooked (and have been since that fateful summer day). But the sadistic joy of playing with him was intertwined with this rush of lust;
 "Who is the prettiest little sister in the whole world?" I asked. He looked at me confused and I closed my legs and put a piece of the t-shirt firmly between my legs. "well who is the the prettiest sister in the whole world?" I repeated "ummm, you are" he said " that's right " I smiled and spread my legs a bit but kept the t-shirt tucked between my thighs. Looking anticipatory between my legs I said "And who is going to to all the pretty little sisters chores for a week?" I said as I grabbed the t-shirt on the knees "ohh, what, umm I will. I will!" and as he said that I pulled the t-shirt up stopping halfway, spreading my legs real wide, 
"Hand me your towel" I said, "I need it just real quick" "But, but no, no - I need it" 
"ok, it that's what you want! MUM! DAD! I NEED A TOWEL" I half shouted
 " No, No! Ok, you can have it.. I guess..." 
And as he very slowly and reluctantly pulled away his towel to reveal his rock hard, slightly throbbing, beautiful penis I equally slowly pulled up my t-shirt to reveal my glistening vagina. In that moment just a slight gush of air right then would surely have given me my first orgasm. 

This is how it started and it went on from there; there was no lack of imagination in my little brain but I don't think the details are that interesting. Suffice it to say that there was not a lot of time that I didn't try to keep my poor brothers mind totally dedicated to sex, my body, masturbating and fear of getting caught. 

Now I'm a grown woman and he is a grown man but teasing him is all I think about when I masturbate. I continued to tease him all through the years and that's what I'm thinking back to when I masturbate and sometimes during sex too but I feel so ashamed.
 I really, really love my brother (no, not like that, like a sister) and he is so sweet and has always been there for me - still I can't stop doing it.
 
Just to take a fairly regular example:Even now I sometimes call him when I'm desperately horny and have this strange concealed but obvious phone sex; I tell him about some boy I've been with and what we have done in graphic detail, or I just tell him that I watched this film or saw this guy on the subway that really turned me on or that I've been watching porn all day, casually drop in the conversation that i have just taken a bath, shaved "everything" and slipped into a thong and nothing else and now getting into bed and then I basically stop talking but moan sporadically as if I'm trying to hide that I'm masturbating. I know he's horny as hell but he is too nice to ever say something, and even if he would he cant really call me out on it basically because I think that he hinks he is the disgusting pervert for having this bloodfilled penis in his hand while talking to his sweet little sister, so there is basically silence between my moans which grow louder and louder and I ask him what's wrong, you're so quiet, why are you just silent listening to me? Why don't you hang up the phone? Is everything alright? between my increasingly vocal moans until I climax. 
That's pretty bad I guess but I've done lots, lots more but I don't think describing them would really add anything. 
I really don't know why I'm doing this. He's tried to tell me a lot of times, usually when he's a little bit drunk, how sorry he is for "not being a nice brother" when we grew up and I basically just stop him cold before he gets the chance to say that he's sorry for having molested me or something when I was young. Obviously he didn't, but I guess he feels guilty for masturbating in front of me and such. Not that he wanted to - I basically forced him to do it or I would threaten to expose him. The closest thing to molesting me was when used to beg him to sleep in his bed because I said I was afraid of the dark and then strip naked and lying, pretending to be asleep, trembling with anticipation until he couldn't stop himself from touching me and sometimes even lick me. I came and I came hard sometimes just from the breath of his mouth against my vagina. But then after a while I pretended to wake up and not understand what was going on and acting confused and he got so ashamed, only for me then to "fall asleep" and "accidentally" touch his penis in my sleep and watch, lying with my head on his belly staring through half-closed eyes how he masturbated while I had two of my fingers inside of me. Another favorite was when we were alone in the house at night. I liked to cuddle close to him, take the remote and switch to the porn channel on cable and then ideally I would go to my room early and start to masturbate with my door not fully closed. Bucking wildly, almost screaming in the end he couldn't help himself but after a while he would go in to my room to watch. After climaxing and laying passed out naked I would suddenly come to and and ask him flat out what the h**l he was doing in my room.

Sure it is reciprocated in so much as he's probably  attracted to me, or rather perhaps the incest part of it. A lot I would guess. But whichever way I slice it I'm always the instigator. Perhaps he would be thinking of me anyways while he's masturbating (but I'm not sure about that obviously). But there is something sinister here I feel, and it comes from me. For instance; For his birthday a couple of years back I coaxed one of my girlfriends into giving him a blowjob but (gross as that may be in itself) - I didn't leave them by themselves but undressed her, showed of her body, forced her down on the floor, sat on my knees behind her telling him how fu***able she was and taking her by the hair forcing his penis in her mouth and continuing to force her head in and out while looking him in the eye and asking him if it felt nice, if she liked his sisters birthday present and so on. Not cool, right?
So what should I do? (ok, I know the answer to that - just stop - but I've been trying but not hard enough I guess)
The other question is - how f****ed up am I. (ok, know the answer to that to..) 

But you can't go into a erotic short story site without being bombarded by guys describing fantasies about incest sex written be males from a male perpetrator point of view, but every time I see a woman writing about sister/brother relations it's invariably girls who have been taken advantage of, either by physical or psychological molestation or being tricked into it at an early age and complying out of wanting approval, fear or low self-esteem. Sometimes the odd novel comes about about a Romeo/Juliet romance between sister and brother.  Never do I see stories of women fantasizing about seducing their brother out of sheer sex drive? Is it really that uncommon?

It sounds to me like you are likely to have complex reasons whether they appear traumatic or not for behaving in the way that you do that you may or may not want to work on. I dont know how common seducing your sibling because of sex drive is but I dont think it is common based on my experience here - tho of course that may well not be accurate. Have you ever thought about trying to untangle this with a therapist? I think they are the ppl who would be able to accuratetly help you understand it.

Cracked

I don't think you should feel ANY SHAME or Guilt for this behavior... I truly feel that YOU are just one of the RARE Human Beings that are HONEST enough to Post this for ALL to see... I think THIS BEHAVIOR OCCURS ALOT more than PEOPLE DARE to ADMIT to!

What YOU should do is have a REAL... Awkward... OPEN and FRANK discussion with your Brother about this... You are both Adults and I think its VERY IMPORTANT for BOTH of YOU to OPENLY TALK about this... No matter how Weird and Awkward it will be... I think it will take ALOT of GUILT and SHAME away from the BOTH of You...

Good luck... WOuld love to know the outcome of all this... Truly FASCINATING Story and THANK YOU for being so BLUNT and Open and HONEST!

Don't Beat yourself Up about this...

I think you should feel some guilt because although you were only nine years old, you're brother was also young at thirteen years old at the time. Your brother was probably sexually developing himself at the time and you basically used and manipulated him. Now he feels guilt about having molested you at a young age and who knows how that may affected his psychological development.

Having said that, how does a nine year old come to have knowledge of all of these things if she wasn't sexually molested at some point?