Help, I don’t understand ex wife behaviour

So I met my significant other while he was separated- 9 months ish separated and already living on his own and paying for a divorce lawyer. Two months into our relationship his ex tried to add me on fb and sent me a msg claiming she is his ex wife and that since they have children together they will always need to be in each other’s lives to co parent etc. I agree on positive co parenting but I didn’t add her to fb since our relationship was so new and I was just getting to know him and haven’t even met his sons, I even explained to her that this was a new relationship and I need to see where it goes first ... plus personally the kids are old enough that her and I don’t need to be friends on fb. 14 and 16 yrs old. She was pissed I didn’t add her to say the least.

Fast forward a year into dating my significant other. I only met the kids once, which the youngest said I was nice and that he liked me ( we took him to a movie ) eldest didn’t want to meet me because of what his mom has said but I had to drive my boyfriend (after working night shift) to go pick the child up after he got into a car accident since mom was out of town and he was home alone (which she didn’t tell the dad). she quickly went on fb and posted she wished her kids wouldn’t be so nice to strangers and that she wished they would be little assholes just once!

She’s told both boys that their dad cheated on her and left the family, since they were only separated and not divorced that counts as cheating and the children I guess need to know this ( keep In mind she’s had a boyfriend in that time but I guess that’s okay ). She’s told the kids about their divorce, she’s yelled at him Infront of the kids, kicked the side of his car (two grand worth of damage) yelled at him at their hockey games etc.

She’s made fake Instagram accounts and has tried to add me and had her family attempt to add me. She’s tried adding my friends etc!!! I came to one of the kids lacrosse practices and she came over and screamed at me that I needed to leave because her son didn’t want me there, dad could stay but I had to go wait in the car— we both left because how embarrassing for the teenager infront of other parents and his friends.

She won’t give my significant other of any of the kids sports events because apparently neither teen wants him to know because he might bring me to their games, they will only allow him the information under the stipulation that i don’t come since I’m a “homewrecker”. This is recent behaviour.

I’ve called her out on social media publicly for making fake accounts and adding me and my friends as well as having her family try to add me. Cause I’m not taking that bs. My boyfriend has also called her out on it and she just skips past it and ignores it. Doesn’t deny it, just ignores it.

The last kids hockey game I went to, we got a text after saying I shouldn’t be on my phone if I come and he should have his arm around me In the stands- text from his 14 year old who was on the ice playing hockey ( I was texting my mom because I had recently had an ectopic miscarriage) the text is written how hers normally are so we figure it’s her using the child’s phone.

It’s at the point now that she calls me my significant others “friend” and that they don’t speak my name in their house. That the kids need to be his priority only , that they want nothing to do with me, hear my name or see me. If they hear of me, see me than she won’t give their dad their sports info because that’s the stipulation of the 14 yr old and 16 yr old kids.

She sends him messages about how he isn’t a man because he walked away from his kids and broke his promises to her that he wanted to chase women openly and put women before his kids (he’s dated me and briefly one other lady since leaving) that he replaced her ... that the kids have been her rock as they have seen her hurt and seen her pain (im wording it how she does) and that they are strong and all healing together, that she picked up their pieces, that she lets them know that SHE will always be there for them... ( so I’m assuming she tells them their dad won’t always be there for them?!?).

My boyfriend texts the kids every night telling them he loves them and misses them and wants to see them. He tried calling but both texts and phone calls are always unanswered.

She is very quick to send my boyfriend the receipts of any section 7 stuff he has to pay though, he pays 87% of it. She also tried to get him to pay for their school fees which are section 3 (that’s what the 1,800 a month he pays in child support goes to)

In April it will have been a year since his kids have talked to him and the courts won’t touch it since they are technically old enough to make those choices. He has axles for counselling for the kids but they say no and mom says she respects their wishes to do what they need to do.

My boyfriend of over a year now and I are living together and trying to a baby of our own. Which I’m sure she’s going to freak when that happens :(. Which I really don’t want because I would love for the kids to view each other as siblings and get along. I don’t want to replace these kids’s mother (they have one, bitter as she may be they will have one). I just want the kids to see their dad and spend time with him. I’ve been staying away from their games even though some people say go cause the kids should she dictating their fathers life. I don’t know what to do, we aren’t separating I know that much, but this woman is lying to her own children!!!

Now I don’t know any of you ladies so I would tell you if we cheated and I would understand better why she’s acting the way she is if that was the case. But we didn’t and she knows it deep down (since she hacked his online dating profile found me and sent me that fb msg!). I’m hurt that someone would go to this level and hurt kids and their dad. Why do people do this shit?!

Help ....