My sister... my parents are a wreck and her son hates her

OK, I got a shitty message so I'm just going to explain the situation in one post.

My parents are not anti-choice. She was cheating and there was a huge chance the baby wasn't even the same race as her boyfriend. We found that out months after the abortion because she gave her son an old phone of hers and didn't delete the pics... including the ones of her having a bareback threesome with two dudes of a far different skin color than her boyfriend). My parents had bought her and her teenage son from her first marriage with a crackhead a house after her second divorce and she was technically renting it by making the payments on it. After she started dating her boyfriend, she stopped making payments because she was planning on moving soon leaving my parents with the bill so they put it up for sale since she was rarely ever there (her son was though... alone... for school most of the week). She got pregnant after cheating on him and there was a big chance the baby wasn't even the same race as her boyfriend. I was pregnant and my fiance and I were super excited and scared because I have Crohn's and was told I was sterile.

Instead of just being honest, she concocted a whole bullshit story about the baby being sick because she knew her boyfriend was probably going to dump her. She told us that the relationship went bad because of the stress of the miscarriage. She had my parents take the house off the market, pay 5 months of back electricity bills, 5 months of cable/internet (she needed internet for the whole 2 days a week she was there for work but she didn't need HBO), forgave the months of unpaid rent and didn't ask her to start paying rent again for another few months... at which point she moved back in with her boyfriend and left the house a mess (she had three cats that she literally just left there all week after throwing a bag of food in a big bowl and she filled the bathtub with water for them to drink) and my parents finally sold the house for far less than it was worth because they were about to lose their home.

Then it turns out she had an abortion and used the situation to avoid taking responsibility for her shitty actions.

We found out because her boyfriend and her were having a drunken fight and he was going to tell her son the truth to piss her off... so she told him first.

I know abortions are emotionally taxing, but this was her fourth one so she should have been used to it by now or smart enough to start using protection. So yeah, to the few assholes implying it's my parents' fault for being so hard on her... they weren't. At all. Nobody wants to take responsibility for their own actions anymore.

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