Is OTHER wrong in the post ? POST : I've invited a bunch of my friends and my brother out and said they're welcome to bring their partners.

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Immediately after sending the invites I receive a text from my brother asking if I'll invite Betsy.

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This is a rerun of a conversation we had last year, where I essentially said no, I won't invite her. He kept asking and I held my ground. They're not technically dating, despite him clearly being crazy over her. He's over there most evenings but this has now been going on for years and they'll briefly date then break up because they're a terrible couple.

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My reasons for not wanting her there are multiple, we'll start with those not relating directly to my brother:

\- She propositioned one my brother's best mates (who I'm also friends with, we'll call her Flange) boyfriends on a night out. Flange was on holiday, so she'd never know was her argument. The boyfriend turned her down and told Flange. Betsy has given me two different stories on this and has reason to lie, so I believe the boyfriend who is a decent guy and adores Flange.

\- She slept with (another) one of my brothers other best friends (again, who I'm friends with) while she had a boyfriend with whom she has two kids with.

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These are all things that happened before my brother knew her, in fact he started talking to her just after she propositioned his best friends mate. His judgement is not sound. 

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My brother loves to white knight, and she's a single mother with a severely disabled child, so she's essentially his wet dream. To her credit, she's a really good mum and the dad is barely present when it comes to the disabled kid.

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I gave her a chance when they started hanging out and briefly dating. She's a prime example to me of someone who is fun enough to be around but has a terrible character.

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I inadvertently managed to break them up 18 months ago when, on a night out she was telling me how I should be more like my brother with dating and I, somewhat drunkenly (and I AITA here) replied "I'm not planning accidentally knock up an 18 year old". She apparently didn't realise how old my nephews mother had been when they were together, she freaked out at him and broke up. A few days later my brother, devastated, asks me to talk to her. I do, and her response is basically that he's a child molester (to clarify, he is not and all was above board). I am frankly done with her at this point. If that's what she thinks of him having known him then she's not worth my time.

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Anyway, they patch things up because she gets lonely and wants company a week or so later but are "just friends". He at her beck and call. He still chases her, she still leads him on, letting him think they'll be together, a month ago I was told by a third party he had a girlfriend. When I asked him if they were dating again it was "not official yet". It still isn't and her Facebook profile repeatedly states she's single.

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She's said previously, by my brothers own admission she doesn't love him and likes him because he buys her things. None of his friends like her but they tolerate it and don't tell him what they really think. 

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I don't want to encourage this, or have Betsy there on my birthday. I've said partners are welcome and if she's his partner then she counts too, but I don't want her there and I won't extend a personal invite. AITA?

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