Having her close her legs during oral sex may help. Start with your torso more or less vertical and her legs on your shoulders. She slowly lowers herself down and guides herself onto your shaft until you are fully inside her. While both standing and facing the same direction, bend over as far as you comfortably can, and have your partner penetrate you from behind — while in public just make sure you're aware of your state's laws. If you have a free hand, a clitoral reach-around or playing with her breasts can add extra stimulation, too.
Sex Position: Waterfall
She lies on her back and rolls backwards until her legs are over her head. Have him hold onto the back of your head. With your partner on their knees and you facing them in doggy style, give them a blow job.