Ler her.

 “You have me at a disadvantage,” you tell her with a smile.  “Just try not to be too rough.”

   Miki titters at her own sense of power, finding no end of drunken delight in having your firm prick as a personal plaything.  Rather like trying to make someone laugh during church, she plays and teases you relentlessly as you try to concentrate on your driving.  She flicks at your glans with her fingernails, the rubs it over and over in circles with the pad of her thumb.

   You actually start to feel dizzy from the pleasure, still focused keenly on the road.  By now she has managed to work you up so far that you’re seeping pre-cum onto her eager fingers.  This sign of your arousal only encourages her further.  She encircles your cock in her hand and roughly jerks you up and down, her fist ravaging you without mercy.

   “It’s gonna happen, isn’t it,” she taunts you, “I’m gonna make you come, aren’t I?”

   You glance at a nearby street sign, trying to deduce how soon you’ll be arriving at her home.  It isn’t soon enough.  Your balls tighten, and you feel that hollow sensation that lets you know that nothing can stop what’s coming.  Gritting your teeth helplessly, you raise your hips off the seat and grunt brokenly as you climax, your semen spitting rudely up over the front of your shirt and all over Miki’s attentive hand.  She laughs out loud, squeezing every last drop from your member, watching it slid down off your glans and down into your underpants.

   “That is so gross,” she observes, pulling her hand away to look at the sticky substance coating her fingers.

   As you finally catch your breath, you pull up in front of the address Miki gave you as her home.

   “I assume this is the place,” you say, nodding out the side window.

   “Oh, yeah,” she says, looking less than enthusiastic.

   Maybe she doesn’t want to head home after all?  What are the alternatives, though?  You could always offer her a ride to your place instead.  Or maybe it would be cool to ask if you can use her bathroom to clean up instead and see how that goes?