Been there done that but I would have opened the car door gottten out and dropped my pants so she could really watch me stroke my nine.It's apparent that she was ok with watching so go for It!
She's not quite sure what see's seeing! Then she figures it out . . . "My bad luck. It's fucken too dark and I can't see how big his cock is OR, if it's shooting a shitload of jism right now".