[BamaFan121s]

Not your fault that he wanted it, but totally your fault that as an owner, you let it happen. And yes, neutered or not, there is a possibility for plenty of "harm in it." He could have been seriously injured. So could the female.
I'm sorry to say, but his sudden change in behavior is most likely a direct result of the decision you have made. Furthermore, the manner in which you posted, making light of the situation, is not likely to win you lots of support. The majority of the members here focus on the well being of the dog FIRST and generally frown upon a disregard for the best interest of these dogs.