I would have responded with everything Kalandra has already said and yes, I have had and still do have boys and girls living above, below and beside each other. To do so, they must be in solid sided cages so there can be no direct contact such as reaching paws, noses or other parts through the bars. Cages need to both be 100% escape proof. No open topped cages when there are a male and female in the same room as some can be relentless in trying to escape to get to the other.
Boys sometimes show absolutely no interest in the girls until dark. My Merlin would hide in a corner from a pursuing girl, showing no interest at all until it was dark and the house was quiet. Obviously he wanted total privacy.
Unless neutered a boy will relentlessly pursue a girl, even a spayed girl to the point that she could turn on him. Personally, I would keep them in escape proof cages with separate play times because even if you do neuter him, there is no guarantee that they would get along. I also would not neuter a male just to house him with a girl as has Kalandra has mentioned, the surgery is involved and more risky than with a cat or dog.