Our old boy is entire. He is not aggressive and has never ever to my knowledge attempted to shag anything other than the sofa occasionally. When we fostered rescues he never tried anything. We have a puppy now who is 5 months and in the las 2 days the older dog has been constantly humping him! It's driving me nuts. Puppy getting no peace. I've tried 'no' 'leave it' and separating them but he cries! but what can I do? Vet advice was that at 6-12 months puppy should be neutered but he's only 5 months. Any advice in how to stop older dog? He's usually well trained but he seems to be incapable of hearing me. Will it pass.