Stubborn, Mean Mil! Please Give Advice!!

Hello everyone,

I have been dating my boyfriend for close to three years now, and we have a very good relationship and are very compatible.  We frequently talk about marriage after college, so that's why I am referring to this woman as my MIL.  I used to get along wonderfully with his mother, but now it is so hard to be around her.  My boyfriend and I are both in college and we live an hour an a half away from where we grew up, so I don't have to see his mother that much, but when I do, she always makes little stabs and comments at me such as, "wow, you look so tired!"  After about the 85th time she said this to me, I told her that she always tells me I look tired, and it surprises me because each time I am never tired.  After I told her this, she continued to tell me I looked really tired the next time she saw me.  Also, she always brings up these girls in her art classes (she's a high school art teacher) in front of my boyfriend and I and she goes on and on about how they have the best bodies she has ever seen and how they have the biggest boobs and other strange observations about their bodies.  She has brought up five or six different girls over the past six months.  I wonder if she is trying to intimidate me?  Who knows.  Occassionally, she brings up my boyfriends ex-girlfriend from about 4 years ago in front of me.  Why?  I can't think of any other reason except that she wants to make me feel uncomfortable.  This all started after we were on a trip in Florida at her condo.  But these are not things that bother me most, this is just an example of the way she acts towards me.  First of all, I should tell you that my "mother-in-law" had an affair on my boyfriend's father about four years ago, and this man she had an affair with someone who happens to be a close friend of my family.  I knew this man since I was five years old so he's like an uncle to me.  (We are all from the same small town). 
        So last summer my boyfriend and I went on a trip to Florida and stayed at his mother's condo.  She came down in the middle of the week, and then it was us three staying at her condo.  One afternoon while we were in Florida, I had talked to my mom on the phone and she told me that her and my dad were going up north to a cabin with some of their friends, one of them being my mother in law's husband.  Later on, I mentioned how they were all going up north not realizing my mother-in-law would FLIP out!  She started yelling AT me and saying very rude and hurtful things about my mother, such as, "Your mom is ruining my life" and "you have no idea how bad she has hurt me!".  She also said, "your mom has to have all the attention on her all of the time!  She craves attention" and other cruel, jealous comments along those lines.  Also, she called her husband and started yelling and swearing at him too!  I feel like she had no reason to act this way, and I know my mom has always been nothing but nice to this woman.  She accused my mom of trying to have an affair with her husband, but I know my mom is very happily married to my dad.  My mom used to work with my MIL's husband for about 7 years, so that is how this man became good friends with both my mom and my dad.  I am so taken back by the fact that she said my mom craves attention because this woman shouln't talk!  My MIL wears very tight clothes, goes to the tanning bed too much, and dyes her hair bright blonde, trying to appear younger.  Like Magda from the damn "Something about Mary" movie!  My mom is a very natural woman and very kind, too.  She is a people person, she doesn't crave attention.  I am telling you the complete truth, and that is why I am so blown away by the fact that my MIL could say such hurtful and untrue things about my mom to me.  After the fact, I found out that the cabin all of these people (including my parents and my MIL's husband) were going to was the place where my MIL started her affair with her husband.  Maybe this is why she is so upset?  But even if it is, I feel she had no reason to lash out at me.  Before all of this, my parents and my boyfriend's mom and her husband always got together for bon fires and fun gatherings because they were all friends.  I did not realize how jealous my MIL was of my mom.  My mom is a nice, sociable, funny, caring woman and I think my MIL is very threatened by that because she has no friends and is very insecure, ever since she had an affair on my boyfriend's father.    
      Well, after my MIL yelled at me at her condo, I felt really hurt and I defended my mom like a good daughter would do.  My mom has always been a very good friend to my MIL... actually, she was her only friend!  My mom was always the last person to be at my MIL's house to help wash dishes after get togethers and to give her advice when she cried unhappily about her relationship with her husband and how she had an affair on her old husband.  When my MIL yelled at me, she started saying other rude things, such as "your mom treats your dad like ****!" ... which, my mom does not do.  My parents have been married for over 20 years and were high school sweethearts.  I have always admired their relationship, so once again, I defended my mom and I said to my MIL, "I think you're just jealous of my mom.  You have no reason to say these things."  And she said, "Yes!  I am jealous of your mom!"  This happened last August, and it has been almost a year, but she still refuses to talk to my parents.  This is really hard on me because I am so close with my family and it is causing me to have strong feelings of hatred towards my mother in law.  Blood is thicker than water.  I will stand by my family.  I should add that my mom has tried to call my MIL to work things out because she was so surprised by my MIL's behavior.  MIL has refused to call her back or say sorry.  My boyfriend understands my feelings and has asked his mom to apologize to me and to my mom twice or three times ever since this happened.  I have chosen to ignore it and I am nice to my MIL and she acts all enthusiastic and nice to me and she acts like nothing ever happened.  She has never said sorry to me for the way she acted or the things she said to me.  Along with that, just recently my boyfriend's younger brother came to visit us at our apartment and he told me that he asked what's going on with her and my parents because he really likes my mom and dad and they like him too.  Then he told me that my MIL told him she doesn't care to ever work things out with my parents again.  Now, this really refreshed my anger all over again because I know that my mom never did anything wrong to my MIL, so she really has no right to act like the VICTIM here!!!  It's so frustrating and I want to see her as little as possible because I feel that she is a toxic, depressed woman and I am sick of her little stabs and uncomfortable comments and I'm mad that she refuses to say sorry!  If she said sorry, I would be mature and say that this whole thing is water over the dam!  She and I used to have a very good relationship and she would pour her heart out to me about how she misses her old husband who she cheated on and how she's unhappy with her husband now.  I would give her advice and I was always there for her.  She was so unstable, and still is.  But we had the kind of relationship where we could chat on the phone and I felt close to her.  Now when my boyfriend and I come home from college on some weekends, I never ever want to go to his mother's house.  (Our parents live about 7 miles from one another).  Lately, I have chosen to stay at my parents house when my boyfriend stops by his mom's house, for example, on mother's day last month.  My boyfriend told me that his mom said, "WHy isn't Kayla here?  Is she avoiding me or is she mad at me?"  And that is when my boyfriend asked her to apologize for the way she has acted towards me about my family.  Then she told him that she feels that she has done nothing wrong and therefore, should not apologize. 
    I just want this woman out of my life.  She is very stubborn and has continued to make little stabs at me ever since her outburst in Florida last August.  We have gotten along fine since then because I have acted civil towards her in order to make things go smoothly as possible.  But ever since she said she doesn't care to work things out ever again, and that she STILL thinks she did nothing wrong, I don't want to see her.  My boyfriend understands that, but I realize that this whole thing is probably only going to get worse and I feel sick to my stomach whenever I think of having to go to my MIL's house.  But I have to go over to their house this weekend and next weekend because my boyfriend's younger brother is graduating from high school and there is a ceremony this Sunday and the graduation party is next weekend on Sunday.  This is where I really need some advice.  When I arrive there, I just want to be civil with her and say hi, but that is it.  I do not want to give her anything more than a smile and a polite hello, because I have put up an emotional wall towards her and I feel that she doesn't deserve my respect or even a conversation from me.  Is this behavior okay?  Do I have a right to feel this way?  If not, how am I supposed to act towards my MIL for the sake of my boyfriend and our relationship?   Please give me some advice.  Thank you so much for reading this!