As a kid, I started masturbating at an early age. And it helped my little dog would lick anywhere I pointed to. One if the best feelings was to have her lick my ass as I came. Just the feel of it when it pushed into me. The fun stopped when I started getting pubic hair. She would start licking my balls and then asshole, but would grab my pubes and pull. I've never enjoyed pain.
Then when I was about 15, my new neighbors moved in with a border collie named Whitney. Much bigger than my own dog. Extremely friendly too. Never barked or snapped at people. She stated outside, in a fenced in area. I would usually sneak over after dinner to give her some leftovers. One night I gave her a couple slices of roast beef. And had a thought of this dog licking my ass. Where I stood was dark, and I couldn't be seen. I pulled my pants down and stuck my ass through the fence. She gave a little lick and stopped. I placed the meat between my ass cheeks, then let her eat it.Then aimed my ass in her direction. Oh my god! Such a big tongue, pushing inside if me... Gave me one of the biggest hardons I can remember.
I started playing with myself, at the edge of my neighbors house, pants at my feet. While the dog licked me from the inside out. I had to cum! Standing and facing her, she started slowly licking my dick. Per cum and all. I couldn't take it any longer, and started cumming.
It squirted onto her tongue, and she kept licking my dick until the last drop came out. That was my last thing with an animal. I felt ashamed of myself, and have never told that story to another person. ( but I have replayed it in my head while jerking off)