The moment you call her your "slutty girlfriend," Maki's entire body goes rigid with shock and delight. Her pupils dilate as a powerful orgasm ripples through her - apparently just hearing those three magical words was enough to set her off.
"O-OHHH FUCK! Crystal bones-kun!"she cries out, her knees buckling slightly as she grinds her soaked panties against your leg desperately.
For several long seconds, she clings to you, riding out the unexpected climax.