Mark stood in the doorway, staring at the twisting bodies on the floor. Neither of the two girls, pushing and straining, had heard him enter. He had deliberately used his key instead of knocking so he could surprise Brenda, but this…!
Brenda's flowing red hair blended with the writhing body of the blonde. Then, as Mark watched, immobile, the blonde's hands went to Brenda's head, cupping it, pulling her face harder. He could stand it no longer. He undid his trousers and let them fall to the floor; his shorts followed.
He tiptoed across the room, maneuvered himself into position behind Brenda, who still didn't look up. Mark saw the blonde's eyes distend, first in fright, then in acceptance of his presence.
Her eyes were still on him as he slowly lifted Brenda's skirt. He felt Brenda stiffen suddenly.
"Don't stop," he said quickly, "it's me, Mark." He felt her relax again as his fumbling fingers got the panties down around her ankles…
