Brandon can't stand to watch his sister and Zack any more.

"Stay," Lisa said. She gave him a pleading look, her other hand still in her shorts.

Brandon hesitated, then shook his head. "Can't," he said. Brandon stuffed his erection awkwardly into his shorts and walked away.

Without Brandon there, Lisa's pangs of jealousy overcame her arousal at the sexy scene on the couch. Especially since it was so like that time with Zack. Lisa pulled her bikini bottom back into place. She leaned over the counter and hid her head in her folded arms. As Madison's voice rose in orgasm, Lisa's tears flowed out, wetting the fold of her elbow. She tried to take deep breaths. Support them, Brandon had said. She sniffled and shook her head back and forth in her arms. Zack's voice cried out as he reached his own climax. Yes, support them.

Lisa felt a comforting hand on her back and a quiet voice.