Depend on the dog and training. If u show him how to be quiet and u are extremely careful, a blowjob can be one of the most pleasurables things for both, u and your dog. A few k9 may reject it cause of their nature, but from my experience most of males love to be pressed behind the knot while you caress and play with the tip of his cocks using your tongue and salivate over the shaft. If u work correct, u will have a great cock cumming during a half hour and ready to be worshipped, even some dogs are used to be nonstop licked along their penises and let u put them inside your mouth . Warning: no teeth applied or sudden hand touchings