Teenage love

You know those commercials about the "when does caring become abuse" where the boy is constantly texting his girlfriend while dressed up like a giant cellphone...you know the one "nude pics. send some."
Well, what happens when it isn't just texting...and when it isn't the boy trying to control the girl, but the girl controlling the boy?
Im worried about my youngest brother, Jake. He has been seeing a girl for a little over a year now. Jake is 19...this girl, Bridget, is 16...just turned 16. She is the most manipulative, bipolar, slutty, controlling, disrespectful little girl I have ever met.
My brother is not the brother that I know. He is a shell of himself...completely devoid of the person he once was, now just a slave to her. He isn't allowed to have any friends and therefore has none. His old best friend, Dawson, talks to me and is constantly worrying about Jake. He misses him, but no matter how many times he calls or texts, he gets no response back. And it's not just friends. When Jake worked for the same company as my husband, he called off so much and left early so many times because Bridget would call with a "migraine" and "NEED" him, that he lost his job there. He told my mom that he quit, but in reality, they fired him...it destroyed the relationship between Jake and Kevin. Now, Jake hardly sees his family. He comes home from her house and goes straight upstairs to talk on the phone with her until he goes to bed. He isn't happy, but he won't leave.
She has him beat down...convinced that he isn't good enough, worthless, unwanted. Jake is the last person I ever thought this would happen to. Jake is beautiful...I mean, gorgeous. Everytime I show someone his picture, the first thing they say is how attractive he is an they immediately either want his number (if they are younger) or want to know if he is single (if they are older, for their daughters.) He was approached by Abercrombie to model...did he, no-she wouldn't let him.
He had a learning disability all through school and was always down on himself about that, and I think she has exposed this side of him more and made him believe that he isn't worth anything. It drives me crazy.
I sat and talked with my mom and stepdad for 3 hours last night about it. They are so concerned and at a loss of what to do anymore. They are afraid they are losing their son. I watched as my mom teared up and my stepdad (who I have NEVER seen cry) held back tears and choke up as he told me how scared he was.
Her family is crazy. Her mother is bipolar (literally) and the father has no backbone. Bridget is made to have no responsibilities and is given everything she wants whether the family can afford it or not. She believes that the world revolves around her. He older brother had 2 children and another on the way that he has nothing to do with. He had a dishonorable discharge from the navy and is a coke addict. He is a waste of breath. He thought it was funny to teach his oldest son to call his new dad, a black man, a nigger to his face. Nice guy, huh. Worthless. Her younger brother, who is 9, calls his mother a bitch on a daily basis and tried to stab her. What did the mother do? Nothing, just left the room crying. No punishment, no talk about it afterwards, nothing. Her mother thinks it is completely ok to have Jake listed as Bridget's emergency contact on her school card.
The way she dresses is beyond ridiculous. Low cut shirts with her breasts hanging out, teeny-tiny skirts that barely cover her ass. You can see the embarrassment on Jake's face. He talks about how mad he gets when they go out because guys comment about how slutty she looks. Does she change how she dresses to make him feel better...no, because she loves the attention. It doesn't help that I know she cheats on him. I have a list of boys names from a girl she goes to school with. It is sick. And what would Jake do to these boys if he found out? And can he understand that he will go to jail if he takes action against them? He is 19...they are under 18.

What scares me the most is that Jake doesn't see how messed up all this is. He doesn't see that she doesn't love him, she is just using him for money and because she can control him. He doesn't see that he is pushing his family away and hurting the ones that DO love him. He has lost all of his friends. He can't enjoy the things that he used to love in life. When he got a deer this year, he couldn't tell her for 3 days because he knew she would get mad because he went hunting when she was at school. Jake used to hunt every single day during hunting season...it is his passion. He is good at it but apparently now, he has to have a 16 year old's permission in order to do anything. It is just sick.
I don't know what to do about it. I can't stand to be around her. She is fake and I have caught her in too many lies to deal with her anymore. I hate how she treats my brother. I hate what this little girl is doing to my family and I worry about how much more worse it will get. I am truly scared that if they do break up, he will try to kill himself. I know he would. I don't question that at all. She has destroyed my brother and I hate her for it.
I wish terrible things for her, things that I can't say on here. I know it is wrong. But it would solve everything.
I wish she would just disappear. I wish Jake could see that he is worth more than the thoughts of a 16 year old girl. I wish. I wish. I wish.