And DP wins again! Well, mostly.

So apparently, SD12 forgot her transit pass for the millionth time.
DP called me last night as I was going home, warning me that SD12 could ask me for help on her way out, and that he refused to help her - because she forgot her pass doesn't mean that someone will bail her out - AGAIN. OK, thanks DP! (SD12 and I cross paths to/from the city several times a week)

So she does come up to me in a flurry..."Cover, Daddy said he'd call you and that you'd pay for my pass..." No, he didn't. "But...but...I forgot my pass..." Well, then you will just have to pay them tomorrow, I don't have any money on me. She gets this really worried look and says, "Ok....." as she walks off.

I get home and let DP know what happened, and said to him that she even said you told her I'd pay! DP says, "Well, I did tell her that."
Me, WHAT? No. Seriously? You know I don't do that.
DP apologized (I think he tried to make ME the bad guy) and said, "You would have helped if you could have. I told her that if you paid, it would be a loan and she'd have to pay you back."
Me, No, you don't promise her money from me without MY agreement. And you know I would never have agreed. She needs to figure out how to keep her transit pass IN her bag (why is it not in her bag in the first place?). Those guys will stop letting her on, I promise you that. Then what? What will she do then?

He listened, agreed with me and apologized again. Good.
Then he said, "She does need to learn this the hard way. She left her pass here and I could have brought it to her..."
Me, Wait, she left it here and not BMs? She's not had it for DAYS now? She owes the transit people (over $20) a lot now! HELL NO. She needs to pay them back every penny for their good will, which she will lose.
DP, "Yes, I know. She could have asked me earlier to bring it to her but she waited until the last minute as she was leaving school - I wasn't going to drop everything and bring it to her."
Me, And you shouldn't. You made a good choice.
DP, "I guess I need to let BM know what she owes the transit guys..."

SD12 also wants, on the last day of school tomorrow, to go with her friends to hang out with them for lunch before they go home. Which is fine with us. However, this means she will have to take the local bus home, not the school bus, which doesn't run all the way to our neighborhood in the middle of the day. DP will be in the city and I'm at work. Her friends are going home via another route (not their parents). She's been told she can take the regular bus and be dropped off about 1 mile from the house (a good, safe walk). She's complaining about having to walk, it's too hard, why can't her sister skip her karate class, etc., etc....
1) Your sister is not skipping something she's dedicated to and enjoys because of your plans.
2) DP has to work.
3) If you want to be independent, then you need to be able to handle situations in which you want to make special plans, then you need to figure out how to deal with the to/from.