Welcome to the joys of owning unneutered animals. Just a caution always which I think you do go out in the backyard when your female is in heat. Boys can be pretty daring and courageous in climbing under and over fences, and I'm not just talking about your two boys.
The other thing is a bitch in season can get pretty cantankerous with the males, and other females ..(there is a reason they are called bitches
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