Ashley's father comes in to her room as Teddy and Leo watch.
Darell was very tall so Marianne seemed small compared to him, although she was of average built. M never considered Marianne sexually, but also never imagined her offering anal sex so readily.
"Well, that's an interesting offer. You sure about that?" the professor sounded surprised. Positively surprised.
"Or we can go to the bathroom and I'll do it by hand" Marianne sounded almost bored. M peeked over the till and saw her tidying up a workbench near the wall, not looking up, while the professor stood behind her, with both hands pushed deeply inside his lab coat. It looked like he was scratching his crotch with one of them.
"No, ass it is! It's been a few years since I tried it. Let's go!" having made the decision, the professor was very eager to get it going. He crossed to the lab door and dragged a cardboard box full of something heavy in front of them, so that they could be opened just a few centimetres.
"Just in case anyone comes in," he said and turned towards Marianne.
She already took off her lab coat, unbuckled her pants and lowered them to her knees, and was spreading some hand cream on the fingers of her right hand. She put the hand in the backside of her panties and took it out, to add more cream on the tips of her fingers.
"Almost ready, give me a minute" she told him.
The professor opened his lab coat and his pants, fishing his penis out. It wasn't hard yet, and he was tugging on it while coming towards Marianne.
"I will also need a moment, so do make yourself ready. It's a pity you cannot help me achieve readiness with your mouth" he smiled.
"Maybe this will help." said Marianne as she spread a glob of cream on her palm and took his dick in her hand. Looking the professor in the eyes, she started rubbing his dick, coating it with cream at the same time. She seemed to know what she was doing, as his dick started hardening immediately, and he let out a satisfied groan.
"It... certainly... does. Don't overdo it, I still want your ass," he said, already breathing hard.
"Ok then, here it is" Marianne said, turning around, pulling her pants to her knees and bending to prop herself on her elbows on the workbench.
Her ass was a little chubby, but round and nice, with a tuft of black hair showing between her legs. It was not visible from M's angle, but it seemed like her pussy was very hairy.
The professor came towards her and tried to spear her ass with his dick, which didn't work. Then he grabbed her hips and tried again. It slipped. After two more tries, she let out a small laugh: "Wait, I'll guide you."
Taking her hands of the workbench, she reached behind and grabbed his penis in one hand, while using the other to spread her buttocks. She tried getting his penis in that way, but it still kept slipping. The professor was red in the face and seemed very tense, biting his lips and not saying a word. M thought he looked very close to coming. His penis was very hard now, the head read and slick with the mixture of hand cream and pre-cum, as it slipped constantly up and down the cleft of her ass.
"Let's do it like this: I'll spread myself and you take the dick in your hand and put it in" she proposed, letting go of his penis and grabbing each of her cheeks with one hand. She spread them widely, her anus clearly visible and open.
Without another word, the professor took his dick in his hand, pressed its head on the half-open anus and leaned towards her.
"Yessssss!" he exclaimed, as he sank the full length of it in Marianne. With closed eyes, he stood and enjoyed the feeling. She laid her head on the workbench, closed her eyes and seemed to be biting her lips with a painful grimace on her face.
M thought this was a good opportunity for a photo. He took several, to be sure some would be sharp. The lab was well lit, and outside it was getting dark, so the phone had no problem focusing.
After a few pictures, professor started moving, in quick back and forth jerks.