I don't have a doggy, but I have a horse. When I ride him, it's never with my clothes on, so I make myself cum two or three times while riding. His movement while walking adds a lot to my fingers inside me. Then, we stop, and getting him hard is rather easy.
I jack him with both hands and, with patience, I'm rewarded with his cumload all over my body. I leave it on my body, climb back on him and ride back, still leaving his cum all over me for as long as I can. Wearing his cum is giant turnon for me.