For Research Purposes Only

David knelt up behind her, took his cock and guided the tip to her arsehole, slightly open and waiting, he could hear a soft little squelching as Olivia fingered at her vulva, he pressed the tip of his cock into her arse, heard her gasp.

"Take a picture of it going in," she panted, and he did so, when she heard the click, she panted, "Now fuck it...fuck my arse...fill it up...ohhh" and she moaned and umpphed, and pressed her bum back at his body, and flexed her arsehole around his cock, this did hurt just a tiny, beautiful amount, and she loved it.

She was resting her weight on her shoulders now, her hand frantic between her thighs, the wetness slipping and sliding around her fingers increasing and increasing.

"Take a couple more," she gasped, the tension deep in her belly getting to her limit, her mind doing its best to focus on the thrusting at her arse, at the growing tension there.

David took a couple of more pictures, then had to drop the camera. His hands went to her hips, firm and heated against his skin, and he started a firmer, harder thrusting into her. Little spurts from her cunt were splashing on to his thighs and balls now, he banged his cock into her arse, the sounds ringing in his ears, the slapping of his thighs against her bum, her gasps and moans, he had to admit he was a little surprised at some of the words coming from her mouth.

"Ohhh fukkkkkkkkkkk," she shuddered, her thighs tightened, David watched the tensing of her back, the skin of her bum tight and tensing, he looked at the rim of her arsehole as his cock slid back and forth into her, felt her tightening and tightening on him, could hold back not much longer.

"Fuck fuck fuck" Olivia was gasping now, then her whole body almost convulsed, "Ohh fuckkkkk," and she had come, and he could do nothing else, with a grunt, and a huge thrust of his hips, he slammed his cock deep, deep into her arse, and the white heat surged through his cock, and he shuddered, and it all exploded into her, and for a moment his mind went blank, and he spasmed again, and another little burst erupted into Olivia's beautiful arsehole, and gasped. The feel of the wet warmth splashing into her bum was wonderful, amazing, her mind lost the words, it was just incredible.

"OH fuck that was so good," she panted, and then, "take pictures as you take it out, please do that, I need to see," and David limply picked up the camera, and took a picture of his cock leaving her arse, another and another of it as it gaped briefly as his cock left it, another and another as it slowly closed, another of a small stream of white that dribbled out after his cock.

Olivia collapsed onto her belly now, and David collapsed onto her back, she could feel the hotness of his cock against the skin of her arse. After a few moments he rolled to his side next to her, and there was quiet, just the slow recovering of normal breathing, and Olivia's continual little sighs of satisfaction. She rolled on to her back, lifted her knees up, closed her thighs, squeezed them shut against the trembling and tingling that still twitched between her legs, and deep in her belly. Finally she felt capable of coherent speech.

"That was just so wonderful David," and she reached across, and kissed his lips, and her breasts brushed his chest, and she giggled as the corner of her eye caught his cock's reaction to the feel of her nipples grazing the sensitive skin of his still panting chest.

"It sure was," David said, "it was fantastic." He kissed her lips, and a new tenderness intruded on the scientific atmosphere, and she snuggled up against him, after picking up the camera.

Olivia looked at the pictures, giggling, and saying "oh my" and making other approving noises. She was particularly fascinated by the picture showing her arsehole just after his cock had left it. It was wide open, she had no idea it could ever have gotten that big, and clearly showed the inside of it for quite a few centimetres, red, and she looked intently at the ridges inside it.

"Who would ever have thought I would have such a graphic picture of the inside of my bum," and she laughed. "It has closed up hasn't it? I would hate to think I'll walk around with my bum hole that big forever." And they both laughed.

"Of course," David said, his cock hardening at the way she was talking. He showed her the rest of the pictures, the ones showing her opening as it closed over to its normal shape and size.

Olivia pressed her body to his, and thoughts, not new ones, moved through her mind.

"Thank you so much for helping with my research David," and they both laughed at the ridiculousness of it. "Um...I did have some other projects in mind?" and she lifted her head from his shoulder, her eyebrows arched, and smiled.

"Oh yes?" he smiled back, and his cock jumped again at the suggestion. "Such us?"

"Well," and she drew out the word, "now that I have such a great picture of my bum like that, I think I would like a picture of...you know...my other hole, after..."

"After it's been fucked?" David was intentionally crude, he loved the way she had been talking in the heat of her orgasm.

"Exactly," Olivia laughed, and kissed him again. They were silent for a few moments. "Are you busy for the rest of the day?" she asked cautiously now, not wanting to interfere with his privacy.

"Not at all," he kissed her, "except for scientific research." And again their shared laughter.

Olivia felt the tingles in her belly rising.

"If we're going to do that," David said, wishing he hadn't said if, and wishing he didn't have to bring this up at all, "it would be best if I had a shower, just a hygiene thing, before it goes...you know.."

"In my cunt," and David's mind nearly exploded with excitement at the sound of her using that word. "Yes, I read that. Besides, that is a new research topic," she went on, "sucking cock in the shower, I've never done that. Never been fucked in one either."

"We have time for all that research today, I'm sure," he said, and they both knew there would be many more afternoons of research.

"Definitely," Olivia agreed, and stood up from the bed, and took his hand, and together, holding hands, they walked to the bathroom.