How could my sister steal my boyfriend?

  • Jun 19th 2025
  • Est. 1 minutes read

Question

My sister who has been diagnosed with Bipolar disorder came to live with me and my boyfriend of four years. She had struggled financially for many years, and my family and I had already helped her with thousands of dollars and countless hours of support. We thought we had reached our limit. Still, I decided to take her in to try to understand what was really going on with her.

I spent countless hours and hundreds of dollars preparing for her arrival, from outfitting her room with a TV, computer, and bed to coordinating her move from Texas to Connecticut. Our family also helped bring her twelve year old daughter and her three pets who needed vet checks, kennels, and airline tickets. We went through chaos rescuing her from near homelessness, but finally she was safe with me in Connecticut. I was genuinely happy when she arrived.

Then two weeks later I discovered she and my boyfriend had fallen in love. I was forced out of the home because the house is in his name. I stayed another month intentionally to prepare for leaving because I learned my boyfriend is a narcissist, something that explained a lot about my experience living with him. I wanted to see firsthand how these two “evil” forces worked together.

Make no mistake, I was shell shocked, broken by pain, and barely standing but what I witnessed in that house was unbelievable. Through it all, my mother, daughter, and close friends were there to help me stay sane while I prepared to leave. Thankfully, I no longer care about the boyfriend.

What in God’s name could drive my own sister to do this to me? Especially when I have helped her through her worst times with incredible support.

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Answer

I must admit that this is a horrible story. Who can blame you for feeling betrayed and confused.

Perhaps it would help to try and think of it this way: “It could be worse, You could be married to him.” In other words, you are fortunate to be out of that relationship and away from him. As for your sister, that is a lot more complicated.

You and your family had good intentions towards your sister. Well, do you remember the old saying that “Hell is paved with good intentions?” Unfortunately, it is true. Another way of stating this concept is to use the term “Enabling.”  In other words, by attempting to help your sister the entire family has made it easy for her to be irresponsible.

It is true that she has a Bipolar Disorder and that is serious. Of course, there are varying levels of severity for that disorder. If she her mood swings are accompanied by audio visual hallucinations then we refer to the illness as Bipolar with Psychotic features or Schizoaffective Disorder. Either way, those symptoms are extremely serious. That is not to minimize the impact of Bipolar Disorder without psychotic features as the Mania and the Depression can be extremely dangerous.

There is help for your sister in the mental health community without you and your family expending huge sums of your money to support her. A diagnosis of Bipolar Disorder usually qualifies a person for Social Security Income (SSI). SSI would qualify her for Medicare and Medicaid, both of which would cover her treatment for this psychiatric condition.

If she refuses this type of help then the consequences need to be her own. I sense that it was with some naivety that you and your family thought that it would be wonderful to help her. Having a Bipolar Disorder does not prevent a person from being manipulative and selfish. In fact, having that disorder often means that the person carries a personality disorder diagnosis.

I regret the fact that you have been badly hurt by your sister but I hope that it has helped you learn a lesson about “good intentions.” She has a mental illness, perhaps does not take her medication, and may have a personality disorder by whose nature motivates her to manipulate people to her own purposes.

Next time do not help, do not enable and do not pave hell with good intentions. There is plenty of help for your sister in the mental health community and I have a hunch, based on experience, that she is well aware of this.

Sorry for your pain and best of luck to you.