Roy was shivering and with the continuing storm, his temperature would continue to drop. Looking at the Thievul who was glancing back at him, he asked for her help.
„Say, you wouldn't be so kind to let me inside you for some warmth? Preferably though the backdoor. ” Roy spoke slowly and slightly embarrassed, but the Thievul understood him neither the less. 
The Thievul got up before rotating herself so her posterior could face Roy, then rose her tail to show him the exit, or right now the entrance. She even wiggled her butt a little, like she was inviting him to enter. Her head looking back at him, smirking at his shivering body. 
Roy gulped, he didn't expect for her to accept so easily but still, he should be careful about her greed. But right now, the way towards her stinky warmth town has opened for him. 
Slowly, he crawled forward until his face was at the verge of touching the tailhole of the Thievul, he could smell the horrible oder coming from it but also the warmness. Placing his pride aside and trust in the female Thievul, Roy closed his eyes then slowly pushed his hand into Thievul's pucker. The dark type fox moaned as it felt Roy's insertion, she grinded her teeth and tried her hardest not to move. Her dirty pucker slowly relaxed and let Roy's head to enter. He felt the extreme heat wash over his face as the horrible smell invaded his nostrils and forced him to breathe in the shit smell. It was so horrible, yet so worth it. 
The Thievul couldn't wait any longer, she had to take control and have Roy fully lodged in her nasty ass. Without giving any signal, she applied pressure on her behind and sat down, forcing Roy's neck, shoulder, chest and even hands to slide in, in one go. Thievul deeply moaned, wiggling her butt in satisfaction as Roy felt the heat reach down his body. He didn't struggle, heck, he thought it would be better if the Thievul analy swallowed him rather than pushing himself in her. He tried his best not to gag from the horrible smell that was his only breathing substance and let his body relax and go soft. 
The Thievul rose her butt a little, trying to use gravity to slide Roy's legs and rear. Inch by inch, they slowly went in, each time the Thievul moaned extremely satisfied and happy. Her dark red butt slowly consumed Roy's legs until with a wet pop, his feet disappeared within the anus and the dirty pucker closed like nothing ever happened. The Thievul moaned one last time, her tongue drooling down before her body falling down on the ground, feeling Roy getting settled in her posterior. She smiled so happy, she couldn't believe that a human would pop out of nowhere and ask to be her butt plug. 
Roy was also seemingly happy, he wasn't cold anymore, on the opposite, he was very warm. The tight bowels of the Thievul keeping him extremely warm. The smell however, was extremely atrocious, like something in there died and is now hunting him. He tried his best to ignore it and settle down, with no way of going anywhere, he opted to catch a long sleep inside Thievul smelly bowels. Roy couldn't move very much, the walls kept him from moving his limbs, so he had to sleep in the position he entered, face deep in Thievul's bowels. He just hoped the dark type fox wouldn't betray him. 
On the outside, the Thievul was shaking her rear from side to side while looking at it, like she was glancing at a trophy she earned. Her grin so wide and proud.