sounds like this intern pastor needs a bit of a wakeup call.
if it were me, I'd probably also be considering moving to the other youth group, I tried 3 different youth groups in my life until i found the one i go to now, which is now my home.
you don't need permission to join another youth group btw, they would all be delighted if you re-joined don't worry, although it might be awkward for you (coming from experience here) at the end of the day, it doesn't matter.
I would put it down to where most of your friends are, sounds like most of your friends are at this inter pastor's youth group, so if it were me i would try and stick it out.
sometimes when the going gets tough you can't just throw in the towel straight away; my youth group gets on my nerves sometimes with the way they do things and i often contemplate changing youth groups, but for me, it's not about what i want, but what others want. There are a lot of guys at youth group that look up to me as a leader and for me to move on purely self-interested reasons would be 'forsaking' them for lack of a better word :P But then again I'm 18.
Seeing though you have already 'quit' youth group, i would do all you can to get into another youth group as quick as possible. If it means that you join this other youth group then that's cool so long as you get some Christian youth interaction - because that's very important.
My advice to you would be to find a youth group and church and stick with it, no matter how much it sucks, change youth groups now but make sure you find a place and stick with it, don't keep changing around.
Just remember, a youth group is never going to be perfect no matter how much you try or others try, at the end of the day, it is the amount each person puts into it that really counts and makes all the difference.
Hope that helps :S God Bless!