I am In ** with my brother in law

I was an "Oops baby", 10 years behind my next older sister but mom and dad always tell me it means I was meant to be and nothing would keep me from being. Mom was told she would not have any more kids after my sister, Her third but somehow a "Miracle" happened and here I am but that's a whole different story.
I met my BIL when I was only 16 and he was 28, He always treated me like gold and he is a wonderful husband to my sister, A great father to their kids, An exceptional provider for their family and an overall nice person except for one flaw, ME!!!
When I was 21 I finished university and moved in with my sister and her husband in the city to pursue my career and my passion, I felt the city was the only place I could do both at the same time and quickly found work that fit my wants and needs and gave me time to dance (My passion).
I spent 6 months living with my sister before I was offered a promotion out of the blue and against my sisters advice I accepted and as always she was right, I was not ready and ended up getting demoted which looking back was a good thing but at the time destroyed me. I went into a spiral of drinking and had the frame of mind that I was not ever going to be considered again or taken seriously and I feel that's where the problem started.
Two weeks after my 22nd birthday I got demoted back to my original position and exactly one month later I had ** with my BIL for the first time.
I went out with my sister and her husband, My sister is not and never has been a big drinker and she tried to go drink for drink with me and her husband who neither of us had a chance of keeping up with but I did better than her and by the time we went home she puked on the lawn and her husbands pant leg before he carried her into the bedroom and flopped her down on the bed.
I had ZERO intentions of doing anything when I stood at the bedroom doorway and asked if we were going to have another drink, He looked at me and laughed saying "Think you can handle more?", Sadly I never forget anything but I wish I would have blacked out and forgotten the whole thing.
He changed into some sweats, Poured us a drink and we sat on the couch, I noticed he had nothing on under his sweats and could see the outline of his ** through his sweats and I don't know what I was thinking but I kind of forgot about who he was and who I was and before long I found myself sitting right next to him.
He was nervous and kind of panicked when I put my hand on his leg saying "maybe we should get some sleep" but I slid my hand in his sweats and grabbed his ** then leaned in whispering in his ear "Maybe we should do something else", It was crazy and wild and exciting and in the end as I was face down with him on top of me I buried my face in a couch pillow to stifle my moan as I experienced something only he has been able to do to me, My whole body tensed up and shook uncontrollably as we came together in an ** that ruined me for ever.
I laid there face down with him slowly sliding in and out of me twitching and trying to catch my breath having what I call "Mini **", It's crazy and I have never had it with anyone else, It's like I come hard and then if he keeps going I keep having ** but don't have any strength to control it, My body convulses and I get SUPER wet, My legs go limp, My arms turn to jello and I lose control of myself making these weird grunting noises every time I come. He is big, Not huge, not Ron Jeremy or anything but by far the biggest I have had and reaches a place inside me I can't even recreate when alone (I have tried).
I met my husband a year ago, We got married two months ago and I have already had ** twice with my BIL. This morning and ON MY WEDDING NIGHT!!!! WHY???...After the reception my husband and I went back to our room, He made the most of the party and barely made it in the door and passed out so I decided to go back to the party, On the way down the hall who did I meet...My BIL, I Instantly started breathing heavy and within literally seconds we were in a stairwell with me bent over the railing, Wedding dress up around my waist both coming so hard it was running down my legs then he pulled out and went to his room to get whatever he was originally on his way there for and i went back to my room and crawled into bed.
I did eventually get my promotion and it was a better promotion than my original with the exception of having to move 6 hours away, I still go see my sister one every two months or so and at least one time during my stay I get time alone with her husband, and this morning was that time. While she was at the store i woke up to him leaning over me nibbling my neck, i was instantly wet and half an hour later he smacked my **, kissed me and walked out leaving me shaking as i tried to catch my breath.
I basically passed out and woke up an hour later hornier than i have ever been but i could hear my sister in the kitchen so I was forced to take care of myself which never gives me what he does and now i sit in an airport awaiting my flight home to my husband.
What is this hold he has on me.
Why can't I control myself around him.
And HOW DOES HE DO WHAT HE DOES TO ME!!!!!