I can't remember what species they were or even if they were male or female for sure. I'll assume they are veileds or panthers. If they are a male and female, they will likely try to mate as soon as they are sexually mature if you leave them together. Do you really want to put the extra calcium/nutritional demands of making fertile eggs on your female who won't likely be full grown herself? If you do, she could end up with MBD.
In addition to that, I have seen pairs of chameleons kept together before, even two females, and one always ends up going down hill and dying if not separated in time. The stress is somewhat silent....you might not notice it until its too late. It might be possible in a very very big cage (how big is your cage?)...but do you want to risk it?? Do you want you female to constantly be stressed having to keep her eye out for the male? They shouldn't even be able to see each other if you want to keep the stress levels as low as possible (which in turn affects the immune system).
Just my opinion. I've been keeping chameleons for over 15 years.