Ask her about happy ending

Although you're excited by the massage, you're still in control of yourself. "So, after massage, what else you can do?"

"I'm not sure. Let him do me?"

"That makes sense. But why not you do something else?" you say as an idea comes to mind.

"What do you mean, My Lord?"

You look at your erect dick, begging for a release. "Slowly masturbate me until I climax," She is about to do it, but you stop her. "With the oil,"

With the oil as a lubricant, Gretha slowly runs her hand up and down on your dick until you climax, spurting your cum. Because she was close, some even landed on her face and hair. Absently, she wiped the cum with her fingers and put it in her mouth.

"Tell your customer up front, you'll charge 1 gorschen for a massage, 2 grorschen for massage and masturbation, and perhaps 6 gorschen for a massage and sex."

"But then I will get fewer."

"True, but how often you have sex each time, compared to how often you can get men off by masturbating them?"

Gretha nodded in understanding. "But what if I want to do it with a man willingly?"

"Then tell the man about it. Tell him you're willing to do it with him for free."

"Well then, My Lord. Will you do it with me?" she said coquettishly while looking at your slightly limp, but still erect dick. "It's free."