I very much doubt a titty fuck would relieve a dog. Considering dogs do not work the same way a human does down there. In fact rubbing the penis with something like your hand/breast would be uncomfortable and borderline painful for a dog. Unless that object is covered in lube. Even then the way you make a dog cum is by squeezing the knot and stimulating the tip. Which is leaps away from someone shoving a dick between the breasts.