Get with the times! Moofy was neutered months ago! And if he wouldn't have been neutered he would have tried to breed with both the mom/sister.. and Monkey would have done the same, which is why he is now neutered.
Males are old enough to breed pretty soon, once their scent gland starts to come in is one indication, Moofys never did come in, I took him to get neutered as soon as he dropped.