Animal masturbation? Best Answer 10 Points!?

When I was 12, we had a small dog named Gomez. He was a "horny" dog and humped everything. I usually wear underwear and a t-shirt to bed. One night, Gomez crawled under the blanket, and started pulling at the crotch part of my underwear. Out of curiousity, I pulled my underwear off and he started darting his tongue in and out of my . It felt so good so I let him do it. I heard of this thing called animal masturbation. Is this what it is?