Falling out with my best friend?

[dazzle]

My best friend celebrated her 20th birthday on Saturday together with some other people we know. She had booked a "VIP lounge" at a club, therefore no one had to pay for their drinks and we all drank quite a bit. Later that night a friend of us came up to me and told me that my best friend sleeps around without using a condom. I don't judge anyone for having sex, I judge people for having sex with strangers without protecting themselves. So I was pretty drunk (everyone was), and her older sister and me started talking, and I let that information slip out. Now I know this makes me look like a terrible friend, but I swear I didn't do it to talk my best friend down, frankly, I'm just worried about her. I tried to change the subject, but her sister wouldn't let it go, so I just said that maybe she could sit down and talk to my best friend about using contraceptives. Well, apparently she told her boyfriend and her boyfriend talked to my best friend, and didn't mention anything but me saying she sleeps around with a lot of guys, which wasn't even my point. So my best friend came up to me in the club and addressed me, and I explained to her why I did what I did and apologized. Several times. And she said it was okay.
Fast forward a few hours later, around five in the morning. Everyone but two of our friends, me, and a friend of my best friend already left a while ago. We were walking to the subway, when my best friend and her friend turned around, started to walk in the opposite direction and ignored our calls. We continued walking to the subway station, and suddenly one of my friends pointed out that they were sitting in a care with some guys and were just driving by.
The next day my best friend texted me saying she was sorry about bailing on us, but that she was pissed at me for telling her sister. I know I should've let it go because obviously I wasn't the best friend too, but you have to know that she's done these things in the past, so it's kind of a sore spot. I texted her back saying that yes, it was shitty of me, but that she never listens to anyone else when we try to tell her it can end badly, and that she didn't just bail on me, but on our other two friends as well. She responded by saying that taking the subway with two other people wasn't as bad as her sister thinking badly of her, which is true, but that wasn't my point, and that's what I told her. Then she said that she doesn't think she needs to apologize a third time - I didn't think that either, I wanted her to understand - and that she doesn't want to burden herself with these things and needs to go to sleep.
Today I asked her if she still wanted to go see Catching Fire with me, and she texted back saying, "Yes, whatever, when exactly?" I informed her that it was tomorrow, and she told me that she doesn't have time tomorrow. She never doesn't have time on weekdays because she doesn't have any hobbies and doesn't really do anything with her other friends but clubbing on the weekends. So, I'm taking an educated guess that she's lying to me and simply doesn't want to.

If you read the whole thing, I salute you! My question is, what should I do now? Should I apologize again, even though she seemed fed up with the topic? I know it would be best to meet and sit down and talk about it, but she isn't the type for that at all. I really don't know what to do.

[loopyloo]

I would apologise and make it short and sincere. Send her an email or note if you are worried about things blowing up face to face. You shouldn't have talked about her. If you were worried about her behaviour you should have spoken to her in a neutral and sober environment. If you wanted to get her sister on board then it should have been done only after seriously considering the consequences. Out of interest why did the girl tell you about your friend's behaviour. I am always a little suspicious of people who feel the need to go around telling people personal information. They often act like they are doing it out of concern, but they are often just stirring or like to feed off the drama.