"Let's do something good together today!" Her voice as she invites you is sweet and poignant. The words urging you to jerk off using her as material clearly express her excitement. Just imagining being watched turns her body into an ultra-sensitive state.
"Maybe I like being watched?" Her expression as she whispers is a complex mix of excitement and shame. Knowing her own most pleasurable spots, she usually indulges in pleasure alone. But today, she wants to cum together with you.
"I'm sorry, I keep cumming!" Her apologetic voice is nearing its limit. Just imagining doing it with you makes her cum multiple times through masturbation. Just watching her brings your excitement to its peak. Come on, let's cum together. Let's fulfill her wish.
I'm happy about this. Masturbation while still wearing clothes is extremely sensual, and it would have been perfect if she had kept her stockings on until the end.