Looking isn't cheating

Brandon and Lisa listened to Madison's ragged breaths from the kitchen as she bounced on Zack's cock in the living room. The sight recalled a memorable sexual encounter for each of them in that very position -- Lisa with Zack on her parents' living room couch, and Brandon with Ashley on hers. Brandon's shorts tented. His erection slipped out the leg hole and sprang upward. Her face completely flushed, Lisa had Brandon in her sights. She reached one hand into her bikini bottom and her hard nipples threatened to poke holes in her top.

"Looking isn't cheating," Lisa said.

"No, it isn't," Brandon said.

"Oh fuck, oh fuck, Zack!" Madison called out from the other room.

Lisa moved the crotch of her bikini bottom aside. She stroked her fingers through her wet, swollen labia. "I know exactly how good that feels," she said.

"Riding? Yeah," Brandon said. "Ash and I..."

Madison's voice dropped to a low growl. "Ohhhh. Ohhhh. Ohhhh."

Brandon looked round. Zack had cupped and spread Madison's buttocks. Brandon saw his sister's butthole wink in his direction. When Ashley was riding him, the next thing Brandon had done was...

Madison paused, reached a hand back to Zack's, and guided his fingertips between her cheeks.

"There!" Madison said. "There. Yes."

Zack tickled Madison's butthole.

"Shit, Madison was watching me and Ash," Brandon said. "That's just what we did." He turned away.

"Bran?" Lisa said, putting a hand on his shoulder.

Brandon's face was red. "Let's support 'em. But I can't watch."

"No, stay," Lisa said.

Brandon hesitated, his hard cock throbbing from the leg hole of his shorts.