Due to the length of my cock, Lilly rose until her knees were half-bent. Once she reached the highest point with just the tip barely inside her pussy, she swallowed hard, anticipating the pleasure to come, then forcefully slammed down.
"Hoooh!!"
The sensation of forcefully penetrating her pussy at such speed made her eyes roll back, her strength leaving her hips, causing her to stop moving, pierced by my cock, her body shuddering with the abrupt penetration, her pussy spasming around me.
"What are you doing when you're supposed to be serving?"
"Sorry, Master... my hips have no strength left."
With her strength gone, Lilly leaned forward with her upper body, her large hips sticking out towards me, her moon-like pale buttocks looking overwhelmingly enticing. Unable to resist, I slapped the buttocks of the slave who couldn't even keep her promise to serve.