There are two balloons, one is big and the other is small.
With special means, the smaller one is inserted in the bigger one in such a way that the openings of both the balloons are available to inflate them with air.
Then the smaller one, which is literally inside the bigger one is inflated. Later the bigger one is inflated with air and the openings of both the balloons are sealed in such a manner that the smaller one is entirely detached from the bigger one and can move freely around inside the bigger one.
So, at this stage, we have two balloons which are inflated with air and one inside the other (the smaller one being inside the bigger one).
Then the question is - how can we deflate/puncture the inner one without deflating the bigger one (that means the bigger one / outer one should be intact in its shape and size)?
You may use whatever instruments / accessories are needed to achieve this.
There are TWO different solutions possible, depending on the circumstances. Perhaps more solutions can be possible too!
During a night / rainy day or anytime for that matter, common house-hold articles particularly stationery articles would come to help.