Playfully

 Nikki looks at you, lifting one eyebrow.  "Anything?" she asks.  "Absolutely anything," you respond.  She says, "Good, give me your boxers, NOW!"  You instantly comply and she tells you to sit down next to you and close your eyes.  As soon as you do, you feel Nikki's hand wrapping around your cock tightly and jerking you off at a extremely fast pace.  She reminds you to keep your eyes closed, and just as you feel you're about to come, she asks, "Do you want to come for me little boy?"  You excitedly tell her that you do and she slows down, keeping you right on the edge of cumming.  "Beg me," she orders, and you do so, begging and pleading for her to make you come.  Abruptly, she stops and lets go, saying, "Not good enough, open your eyes.  When you do, you look around noticing that there are more people on the bus and some have notice what is going on, watching you.

    Nikki now make a show out of throwing your boxers out the window, telling you to walk back to the back and she says she will follow in a few minutes.  You stumble back to Anya and Kerry, still shaking from being brought so close to orgasm.  When you arrive, Anya asks, "Where the hell is she?"  You explain that she said she'd join you in a few minutes and Anya says, "You'd better hope so."  They have you sit between them naked and Anya orders you to start masturbating very slowly while she holds the rest of your clothes close to the window.