Balto, Steele's Bitch
Steele flipped over the wolf-dog like any good sire would, until they were rump to rump, their balls trembling together.
Submission
He stood behind her, ass-to-ass with blaze as he once again pumped his genes into her. blaze was laying on the ground, indigo had stopped using his psychic power after the fifth birth. at this point she was too exhausted to resist his advances.
The Wolf and The Tiger
Then, as one, both wolf and tiger lifted a hind leg and swung around each other, turning until they were tied dog-fashion rump to rump.
Wolf Heat: MATES FOR LIFE
Terra then lifts one of his back legs over silva, so that they stood rear-to-rear. this was a defence tactic, enabling them to keep watch all around them, as they waited for their muscles that tied them together to relax.
Adelaide's Trials: Animal forms, part 1.5
Cian turned himself off of her back and twisted so they were ass to ass. the girl was so tired and worn out that her back legs gave out as well, the only thing holding her up now was the knot that stretched her so completely.
Wolf Guardian
Moments later the wolf got off her back and he stood butt to butt with her, his knot locked firmly inside still spraying his seed in her womb. jenny looked around, she was confused. why were they stuck together?
The forest pleasures (story about two wolves) -2nd chapter-
to rear with her she panted and stood still feeling him fill her slowly from behind they both put there heads downwords and panted she looked at him and he looked back 'how does it feel?'
His Extreme First Time: A Boy and His Dogs
Feeling beef turn and step over him so that they were ass to ass, toni reached out, gently wrapping his fingertips around beau's luscious cock.
Sonnet Redouble
He stood behind me, touching rear to rear, reflecting me in sight as well as sound, our panting with fatigue the same to hear. we stayed there for a while, pending release as his erection shrank to normal size.
Oliver and Company: Offering Some Nub-Tail
His own cock dripped and twitched beneath him, not quite over the edge as roscoe dismounted him, the pair of them standing butt to butt as more and more filled him from behind.
Meeting the Lone Wolf
Shadowfang did end up shifting position so that the human and wolf were now locked ass to ass.
Ginga Densetsu Weed: Hougen's Sins Chapter 1
I then crossed my leg over her back and we then faced butt to butt. my cock throbbed, and then she suddenly screamed, finally understanding what i wanted, '' get it out! i can't have puppies, i'm too young! i don't want puppies, either!