Rex had turned halfway to the side now, his neck arched as he gazed at Catherine. In that position, his prick was in profile. The well-satisfied blonde was smiling with happy contentment but, when she got a look at the Alsatian's meatrack, her smile faded away into an expression of trembling awe.

The dog's long, fat prick was taut and humming like a tuning fork and hard. The bloated slab of his naked red cockhead was pulsing in and out like an inhaling lung, and frothy drops of preliminary jism slathered the tip and dripped off. A trickle had run down onto his hairy prick, matting the shaggy sheath. The cum glistened a milky white on the jet black stalk. His scumbags were like over-inflated balloons, bulging between his hindlegs. His was an impressive hunk of cockmeat – and Catherine was certainly impressed!

Rex whined and his haunches rippled in a humping motion as he stabbed his prick out under him. There was a hopeful and expectant look in his amber eyes. His tongue, still hanging out from the side of his white-fanged jowl and dripping with cuntjuice, was evidence of the fact that he had done his mistress a great service – and that he deserved a reward for being such a good doggy.

Catherine's eyes were glued on the dog's cock and balls, fascinated. It was her fault that the dog had such a lovely big hard-on, she knew, and she felt that she was obliged to relieve the faithful dog. She knew that it must be agony for a doggy to have such a stiff prick and such swollen scumbags, with no place to empty them. Not having hands, a doggy couldn't jerk himself off, of course – but Catherine had hands, and those hands were tingling for a touch of dog meat. She was rationalizing again, as she had when she had decided to let the dog lap her pussy, reasoning that she owed him a come and, also, that it would be a good idea to get his cock emptied and soft before her husband or her son came home.