Your hand is still working your large, bright red, swollen cock when powerful muscles in your crotch tense up. It's starting - reality sinks in that you're about to have your first canine orgasm.
Feeling a powerful orgasm building in your new equipment, you instinctively clutch your bulging knot. As the sensations crest, your doggy dick swells even larger; you've crossed the point of no return. Your body freezes up, your crotch feels warm, and you feel the contractions as long ropes of semen start erupting from the pointed tip. You spurt for what seems like forever, never having imagined that a dog could cum that much.
As you regain your senses, you see that you’ve ejaculated at least a half pint of dog cum all over your legs and bed.