Cons:
Your dog/his parents are unlikely to have had the relevant health checks. Neither is any bitch he'll service because no reputable breeder would touch him. You're opening yourself up to generation upon generation of physical and temperament problem-striken puppies. Cute does not equal good breeding material.
There are thousands of young, healthy dogs dying in pounds each year for want of homes. You will be adding to this by breeding yet more pups. PLEASE, if you do nothing else tonight, That's shot in Ireland but the only difference between there and the UK is that our dogs have 7 days in the pound before they can be by law, and so often are, killed.
Who will you sell the pups to? How will you check the new owners out? Are you going to sell to someone who will take that pup and raise it in a puppy farm where she is locked in a shed in her own shit all day every day and bred from every 6 months?
Is the bitch's owner willing and able to take a dog back - or dogS back - if ever the owner can't keep them. at ANY time in the pup's life, come what may? Thats what a good breeder does. That's what ANY responsible rehomer does and why decent rescues and organisations like the Dogs Trust, Blue Cross and RSPCA demand that you return to them an unwanted dog you've adopted, even if that dog is ill or if it's in 10 years time. Are you/they willing and able to take back a destructive, fear aggressive adolescent dog or one who is suffering from seperation anxiety and who howls as soon as you leave him, upsetting the neighbours? Are you/they willing/able to take back a dog who turns out to be aggressive or who has epilepsy and who needs supervision and expensive medication for the rest of his life? Will/they you still be there in 15 years time to take back a dog bred by you?
Are you willing to accept that the bitch owned person you stud your dog out to may be a puppy farmer? Certainly that they WILL be at best irresponsible - decent breeders don't just become that overnight and they definitely wouln't breed their bitch with a non-registered stud owned by a novice.
Are you aware that an unneutered dog, apart from being likely to add to the already unwanted and dying dog population, is more likely to stray and be lost, a bigger target for dog theifs (and dog theft is rife, see DogLost website for proof of this), is statistically more likely to be dog-aggressive and a target for other male dogs with an aggressive bent as well as being at risk by being unneutered of a variety of conditions including cancer?
Pros:
None.
Sorry, this is harsh, but it's a fact and one which rescue struggles with and breaks its heart over on literally a daily basis. Go to your local council dog pound, see the healthy young dogs in there who have been picked up as abandoned strays and who will be put to sleep after they've been in that pound for just 7 days. Look them in the eye and tell them why you're going to breed yet more puppies just because your boy is cute - though I'm sure he is - and tell them that they are going to die because you're giving the sometimes unaware and sometimes uncaring public the alternative of a cute but non-health tested pup brought into this world by a novice without the experience to get into breeding properly. (If indeed they should do it at all, which for the reasons outlined above I think they shouldn't although I accept that decent breeders are justified in arguing with me. As a rescuer I have equal justification for disagreeing whilst taking my hat off to the Midori 's of this world who do it the right way.
Neither you nor I can change the attitude of the uncaring who will buy a pup from the owner of the bitch in your situation. We can both however change the attitude of the unaware - me by explaining what I have above, you by not breeding from your boy... and that way we can both save the lives of several pound dogs, now and in the future.