Give her the 'medicine'

You unzip your pants and your member springs out. Maria strokes it a few times before licking the tip with her rough tongue and smirks.
"Well, well...I never thought you'd have both genitals Doc." She purrs. "All this time I thought you were one."
"I don't like to show off." You say.
Maria takes your member in her mouth before moving her head up and down it. Her rough tongue and soft throat make you shiver multiple times. You suddenly grab her head, pin her to the chair, and push your member deep down her throat over and over, until you cum in a large gush. When you're done you pull out and clean up. Maria does the same.
"Thank you, Doc." She says.
"Your 'real' medicine is at the pharmacy." You tell her. "The nurse will write you a prescription."
Maria walks out and you breathe in relief. That's done, and now you can prepare for your next client...