Tracey's working on Heidi's clit while she orgasmed indeed caused Heidi's orgasm to be prolonged. In fact, she thought it might just have been one of the longest she'd ever had. By the time Tracey pulled away, Heidi was faintly shaking in the aftermath, her chest rising and falling steadily as she tried to regain her breath.
The finger that entered her cause Heidi to jump in surprise, not expecting Tracey to continue on but readily accepted it with a soft moan. "Oh yes..." She groaned out as she tangled her fingers in Tracey's hair and her other hand gripped the seat of the chair.
"Keep going." Heidi urged as she arched her hips into the finger that curled in her cunt. She bit her lip and looked down, watching Tracey and the finger inside of her.