Birthdays and Bitch Fests.

I never thought that inviting someone to my son's second birthday would cause an argument...But that was also a time before SD dove into the eternal depths that is IB's anus and refused to leave. He managed to call me September 1st to tell me that he would be paying his first child support payment on the 14th, which did not happen. Surprising? Nope, though I wish I could say I was the least bit surprised.
Back to business. After he informed me of his intent to pay, I decided to be nice and invite him to my son's birthday party in about two months. He said "Well can I..." and I quickly cut him off. I said very kindly "You are invited, your mother is invited, your mother's sister is invited, anyone who is family is invited. Anyone who is not family is not invited. Catch my drift?"
"Oh so IB can't come?" I figured you'd catch that and I wouldn't have to explain, but apparently an explanation is in order. "No, she may not." "Why?" SD knows damn good and well why IB cannot come, but he likes to get explanations so that he can repeat it to her when I wouldn't have a problem saying it to her myself. I am the type of person who thinks with a very level head and can be very civil when I choose to.
"She cannot come because 1) I do not like her. 2) My mother hates her. 3) Your mother hates her. 4) I've already told her before that she is not to step foot on my property after the horrid things she's said about my son and 5) If she does so choose to ignore it and step foot on my property, I will have her arrested and do not think I won't."
"Why do you hate her?" "I wonder why? It could have been because she said my son was an inconvenience to your future family, or that she said she hoped he wasn't yours, or any time you spoke to her about my son she would say 'shut up, you don't even know if that's your kid.' so...Maybe all of the above?"
"Well you know we're getting married, she's going to be family, you gotta get used to the fact she's going to be around you and AK..." I again, cut him off.
"I do not have to get used to a damn thing, SD. You can marry her 40 times, that will not make her shit to me. This is my child, it's my child's birthday, I'm paying for it, I'm hosting it, I will say who can come and who cannot and I will not have people pissed off at my kid's party so no, she can't come. You can either come alone or don't come at all."

He said he would come alone, so we will see how that goes.
Stand your ground ladies. Don't be pushed around when you know someone is a toxic influence to your child. Mother knows best.