He is onto something

"The door is open for you. Come inside right now," Nathan commanded. Every hair on my body stood up with nervous excitement. He was ready for me. I could sense that in his voice. I licked my lips and pushed my dress further down to get more cleavage out. It worked perfectly, and my rounded breasts, held up by a decent pushup bra, became decently visible.
With a marvelous plan to excite his manhood, I entered the room, expecting immediate action.
"Shit!" I covered my mouth in shock. Nathan had not failed to make me scream, but it wasn't out of what emotion I expected. There was another person in that room with us. And it was none other than his mother's secret lover, Doctor Williams.
"I suppose there is no need for an introduction as you two are already acquainted," Nathan spoke from the bed. He was resting as Doctor Williams injected something into him via a syringe. "Come, have a seat right next to me. We have a lot to talk about." Nathan's hand smoothened the sheet with inviting eyes.
I hesitated and wanted to flee and return at a more appropriate time. It wasn't anything against what we agreed on. Doctor William's presence made it extremely weird, especially after the shameful act I had caught him in with Mrs. Sinclair.
"Hello, Doctor," I awkwardly greeted him, pushing the neck of my dress upwards to conceal the enticing preview of my chest.
The doctor was equally uncomfortable to see me. He could barely glance my way, let alone look directly at me. He didn't open his mouth until he had thrown the syringe away and had an alcohol pad pressed onto Nathan's arm.
"Hello to you, too," he spoke coldly. There was so much guilt in his eyes. Was Nathan blind to everybody else's lies but me? Or did he only enjoy targeting his favorite victim?
"Come sit," Nathan repeated. "You are the only one who can sit on my bed. Leap on the opportunity while it's still available."
Awkwardly, I approached the bed and sat in the very corner of it. The doctor would likely leave soon, so I only had to remain invisible for a while.
Nathan grabbed my hand, pushing me toward him. "Come closer. Why are you sitting so far away from me? I wasn't expecting this kind of distance after our tongues crossed all limits of closeness."
The doctor coughed loudly, and I turned crimson red with embarrassment. Why did he have to say that in front of him?
"I'll come back later when you aren't busy," said Doctor Williams, hastily leaving his seat.
"Permission denied," Nathan spoke, shocking us both. "You are here to treat me. Do your work and leave. We are not paying you to sit idle and party all day."
I don't know why I expected Nathan to treat everyone better after his gesture of kindness and a steamy kiss on the balcony. He was still the same man, just not as bad of a person as I initially thought him to be.
"I'll leave then. Your treatment is more important." I got up to leave, but Nathan seized my hand, forcing me to sit again.
"No one leaves this room until I tell them to. Don't be so shy, Amelia. Pretend he is not here. I want you to be here while he gives me the bad news." He caressed my arm. His eyes reflected a childlike need for support.
"What bad news?" I jumped on the bed, sitting with my legs crossed. Nathan smiled and silently looked at the doctor.
"Your disease is surprising us," Doctor Williams began. "Since we don't yet understand what it is, all we can do is to alleviate the pain and manage the symptoms." He reached and flipped through the pages of a medical file. "Your test results are not making me happy, Nathan. Even though your condition seems neurological as you keep on losing and regaining your balance and ability to walk, it may have something to do with the physical as well."
"What's your point? Be quick, and don't talk to me in riddles," Nathan demanded.
The doctor pursed his lips. "You should stop doing intense workouts in the gym each time you feel better. I have noticed some problems in your muscles and ligaments. You can seriously injure yourself one day if you are not careful."
Nathan sighed exasperatedly. "Why did you have to say that today, of all days? Sorry to disappoint you, doctor, but I have found a potential romantic partner. She and I can be soon getting engaged or even married? Now, why do you want me to deprive her of my solid body? Even if I leave the gym. How do you expect me not to have raw, animalistic sex every time I see her? That takes more energy than a gym workout."
Oh, my God! I screamed internally at Nathan's choice of words. We stared at him and then at each other in appalled silence. He wanted to do what to me?!
I pinched Nathan's arm, telling him to stop with my eyes.
"I am sorry. We can't hide things from our doctor for our good. There is no shame between a patient and a medical professional," Nathan tried to justify his behavior. Something inside me knew that wasn't the truth. He purposely wanted to make Williams suffer. By any chance, did Nathan suspect an affair between him and his mother?
It took the doctor longer than me to recover and speak. "Your sex life is none of my business, Nathan. I don't wish to intrude or hear about it. All I am asking you is to give your body some rest to avoid injuries and other complications."
"Come on. You're no saint yourself," Nathan mocked him. "I know what you do all day long. You think I wouldn't notice the hickey on your neck?" The color disappeared from Doctor William's face. He knew he was about to get caught. "Whoever tried to cover it with makeup did a terrible job because you can see something was there. I notice these often and only when you are on my property. Are we paying you to fuck or treat my illness?"
Nathan got up and pointed directly at the almost hidden hickey on William's neck. "There is the little culprit. Who gave it to you, Father Williams? Don't force me to open my mouth. I know who you are banging in your free time. I have eyes everywhere in this mansion."