Is over-crowded hinders mating process

Question
Hi, I have 2 pairs of budgie for almost 2 months now and I was wondering if it's fine for them to stay is one cage? The cage is big enough for them fly and play around. Will this also hinders them from mating even if there are others around? Do I have to separate each pair to make this happen? Because I observed that when one pair tries to mate the other birds tries to fly towards them or around the cage and sometimes they make a loud sound making them to stop from what they are planning and wanting to do. This also happened with the other pair.

Thanks.
Dennis

Answer
These interruptions shouldn't interfere with them breeding.  In the wild, they live in flocks of sometimes hundreds of other birds.  I would leave things as they are.  Even though they keep getting interrupted, the stress of moving one of the pairs could bring things to a complete halt.  Since it's only been a couple of months, I wouldn't worry.  

Also, don't be surprised if they switch partners.  Budgies are known for being promiscuous.