I finally snapped and I'm never looking back! I've told both those little brats off and they're getting their a$$es in line!

DH's adult step kids (F33, F26) have been off and on problems for a decade. The latest have been that they completely abandoned their elderly grandparents and wouldn't even call grandfather on his deathbed for the holidays. They don't help us care for them at all but continue to ask us for stuff. And they both caused chaos with our recent wedding. (We've been together for 10 years but just got married.)
 

The youngest scheduled her wedding 2 weeks before ours and then we got stuck doing a huge rehearsal dinner while I should have been preparing for OUR wedding. She did come to ours and behaved.

The older one told a bunch of bald faced lies and caused a year-long family fight. She was having a rough time so we took her for a weekend in Vegas with us for pool and spa days. She came back and told her sister and the rest of the family that DH was incredibly drunk and out of control causing all kinds of trouble in Vegas. None of it was true AT ALL! And in fact she was the one who got incredibly drunk and behaving horribly. We had to stay awake all night to make sure she didn't sneak out of her hotel room and get herself in a dangerous situation. This led to the younger one not speaking to DH for six months and abandoning her dying grandfather because she was mad. (none of this is logical by the way. They can make up more reasons to create drama and get mad than any two people I have ever seen! Emotional blackmail and no contact is their favorite revenge tactic!)

During all this, SD33 hadnt spoken to DH in almost a year, including holidays or when his father (her grandfather) died. SD26 started speaking to us when grandpa died and realized her sister lied and caused all the problems.  SD33 then declined the RSVP to our wedding and included a melodramatic letter in the rsvp saying how obviously the relationship didn't mean much to either of them since it had been a year since they'd talked, blah blah. just trying to get a reaction. We continued to get word from family members that SD 33 was planning on crashing our wedding even though she declined. This went on until the morning of the wedding when the DH finally called her and allowed her attend the ceremony but not the reception. (I didn't want her there, but couldn't keep fighting them on my wedding day!)

On a related note, both of them are super "religious" and carry on about "praying" for everybody. (Of course both of them abandoned their elderly grandparents when it was too difficult so they're really only religious when it's easy!)

So here's how I finally put them in their place! DH decided to continue a relationship with SD 33 despite her bad behavior. I told him I did not want her at my house or around me after what she did with our wedding but he invited her over anyway. She brought her fairly new boyfriend with her and I don't think she was expecting what she got. When they walked in, I greeted them and then told her the following, pointing to our security cameras. "Now, SD33, we have security cameras in the house, and everything today will be recorded. So you will not be able to make up lies about what happens here and try to stir up problems like you did after Vegas. I don't know what new way you will dream up to cause trouble but at least this way we can prove it when you lie about today." I said it in front of her boyfriend and her sister and DH. She was flabbergasted. And she looked like a complete idiot in front of her new boyfriend! She couldn't object, because she was caught red handed-she had told her sister the stories and DH and I both knew what actually happened and had her outnumbered. She was finally caught and called out on her lies! You should have seen the look on boyfriends face! I then went on to tell her that this was just the tip of the iceberg of what she'll be getting from me since she tried to cause trouble for our wedding. It was hilarious and DH couldn't get mad because he knew she was a liar and all I did was point out cameras so that she knew she couldn't lie again!

As for SD26, she was going on and on about something churchy, so I very sincerely asked her how she reconciled her religion with her choice to neglect her grandparents when they were old and sick. (DH adopted both girls-they're his ex's from previous relationships. His parents accepted  these girls as if they were their own, but they completely abandoned them when it got difficult. ) She couldn't answer the question. She just sat there with her mouth open and babbled, but you can't claim to be super religious but not fulfill your basic moral obligations. I told her she was free to do what she wanted, but she needed to be honest with herself that she wasn't as good a Christian as she made herself out to be. It was so satisfying to tell both of those two the blunt truth! It was so funny to watch her try to justify abandoning a dying, elderly couple while talking about what a good Christian she is. DH and I have laughed about that ever since! Hypocrite.

It has been so satisfying not to have to bite my tongue anymore and they're both behaving slightly better since they know they're getting called out!