Is this being rude/unfriendly?

OK so I have been on-off with my BF quite some time. He is living overseas (used to live same country as me for the first 4 years of our relationship), since he moved away things have been rocky. We have been getting together and breaking up for a bit.
Recently we got back together AGAIN lol. We are both older and really want to try and make it work this time. I used to think he never would change (he has some character flaws) but our last break up which was for like half a year seemed to have really helped him make an effort to change, and I can he's trying really hard. I'm also trying to be more tolerant because obviously it's not like a new honeymoon period when everything's always rosy, and it's not like I don't have any flaws myself.
Anyway my problem is I have a very close group of friends. Like about 10 guys and girls. When I say close probably only 2-3 of them are close enough that I would tell everything to, but however the whole group always hangs out together (we do the same course and spend full time Mon to Fri with each other and often weekends too). It's a great group of friends and I really value them and feel so grateful to have them.
HOWEVER as with any tight group of friends, the girls can be VERY gossipy. Two girls in particular while without any malicious intent love to spread rumours about other people in our course, and of course if it's someone in the group it's even bigger news. And not just the girls either I mean everybody loves to hear gossip about people they know right? 
Last time when I broke up with my bf it was hot topic for a while and it really made quite uncomfortable although I knew it wasn't with malicious intent. Also when I was kind of seeing another guy they kept asking me about it and wanting to know how far we made it (not very far at all - and I remember one of the two aforementioned girls gave me a shocked look) and that was really uncomfortable too. I guess I'm a bit of a sensitive person and I don't like drama to be made about me. Obviously I know they are just trying to be friendly and indulge their curiosity as friends.
However now that I am back with my bf I find myself really reluctant to say anything because I don't want a big fuss to be made. For example one of the girls once misheard me say I was in a relationship and in the middle of class (my tutor was the one asking haha) gasped out loud and grasped the guy's arm next to her LOL. 
However is it rude if I don't share this personal information? Like I said we are all friends. In fact I have told two close girlfriends and one close guy friend but I know they wouldn't say anything, I'm even comfortable telling less close friends in the course because they are just like "OK, that's cool" whereas I know my friends will chuck a fuss. 
Honestly I haven't tried to hide it- just not talk about it. A couple of them play with my phone and they saw txt messages from him and so they were asking me about it today. I managed to kind of avoid it for now, but I'm sure they'll get me tomorrow lol! It's a Friday and we're all going out. They're the type to grill me like- why did you guys get back together? I thought you didn't want to date a guy with X/Y anymore.  How long ago? What are going to do about oseas stuff etc etc. Honestly I haven't even thought about these things. Those questions make me super uncomfortable.
So is it rude to kind of say "it's kind of personal" and not share? I'm thinking they might find it rude and unfriendly? I love to chat and I'm very talkative normally and always down to help my friends out and support them in whatever they need, but I don't really want to talk about this particular subject. At the same time I don't want them to think I don't value them as a friend because I don't want to tell them these things. Honestly I do value them but I think they gossip too much lol - but I don't really want to come out and say that and hurt their feelings. 
Opinions?

Nobody is in your situation right now, I gotta say that everyone (including myself) is automatically going to tell you that you're right, you shouldn't tell them everything, it's too much trouble for you, you don't have to tell what you don't have to.

The only bad thing is that even though you're in the right... I'll just warn you that not talking (although not inherently rude) will look rude from the perspective of your friends, who are accustomed to being transparent with lives... your sudden closing up will make them think you're being distant, and as a natural reaction- distance themselves too. Despite this, I think you should go on your merry way and save yourself the drama. There comes a time when you should trust your friends and tell them personal details, but also that a "friend" listening should respect the teller's privacy -__- which in your case- is conflicting. Don't tell them.

yo don't worry too much about it. I'm sure everyone, esp those gossip girls have a couple dark secrets they're too ashamed to let loose. and not even ashamed, they don't want it spread is all there is to it, and they know it can spread...

You are not obligated to say anything to them-even if they are you friends. Personally, I would say "Sorry, I don't like talking about it." However, if you are worried about it coming off as rude you can brush it off in a friendly way. For example, you can say "oh yeah, it just kinda worked out. It's a long story-too boring to tell." and then say nothing more.
 I wonder if you might be fueling the fire by offhandedly making comments about not wanting to get together with your ex or by mentioning something else about your relationship. If you truly want to keep it away from people's ears, try not to say anything to people who may gossip. Otherwise, if you make these comments you are pretty much inviting more questions and gossip. 
That's just my thought...

Thanks. I'm not fuelling the fire... I've managed to keep it under wraps for about 2 months. It's just that recently someone asked me out so I had to explain I was in a relationship to be honest. And also someone in the group look through my phone messages lol

i dont know but being truthful works . then again all those questions and what ifs

You girls and your gossip and drama.

I don't think it is rude to not share.
To be honest, if they are really good friends they should know you are uncomfortable with them spreading the news and realize they should be quiet.
Sometimes there are friends who you know you can share your true feelings with and other friends are more hanging out ones.So don't feel bad. You don't need to tell them the details if you don't feel like it.

Honestly, you don't have to let everybody, no matter how close you guys are, know how your love life is. It's fine if you share with those who are great with keeping secrets! However, I advise that if you're uncomfortable with drama and stuff, then you don't need to share with big mouth people.

If they were good friends, they would respect your privacy and if you don't want to talk about it then they shouldn't push you.

If my friends told me that they didn't want to talk about something, then I would accept it and respect their decision. The only time I think I would push them to tell me something is if I thought it was something that would bring danger to them. In this case, I definitely don't think it is being rude to tell your friends you don't wanna talk about it. If they do have a hissy fit over it then, well they aren't good friends and there is no point in keeping them.