An offer too good to refuse

I've always been really horny ever since I can remember. I only have to look at a girl and start thinking of having sex with her. At 33 single and doing great career wise, I bought my own home, so I would've a place to bring girls. But I lust after them but can't get them to date me let alone let me fuck them. So, I've paid for all the fucks I had until last May. My aunt 51 divorced was having financial problems and was being evicted because of failing to pay her rent. My mother only sister (younger) had blown thru her settlement and thought she would be okay because she had a good job. The company went bust and she lost her job, her children had their families to look after, and she thought she would quickly get another job. No other job found, and she was soon in financial trouble. My aunt isn't bad looking for her age not slim not overweight, looks great when dressed up. Anyway, she had caught me more times than I can remember checking out girls and trying to see down their dresses. Which included her on several occasions, so she decided I was the perfect relative to get help from. Two reasons, first I was the closest as all others lived elsewhere. Second, I was do very well career wise and she wouldn't be drain on me. Also, she thought she had better chances of a good job in the city than elsewhere. I met her as she asked me too and she told me straight of her problems and then made me an offer too good for me to refuse. It wasn't actual sex but viewing rights is a better description, I would be able to watch her undress, dress and bath. As I said it was too good to refuse, so I accepted, and she came to live with me. Not expecting to stay very long, but she found it hard to find the perfect job for her needs. Short on money and needing personal things, she upped the agreement to bathing together. Anyway, while showering with her, I would get hard-ons and she started masturbating me. Finally, one day she decided to use my hard-on for her benefit and had me fuck her. That was in late June ever since I've been fucking her regularly. But I had to hire her as my personal assistant, the sex is for our mutual satisfaction, and she is the greatest personal assistant I've ever had. She is using the job to meet people and may be able to get a good job as a result. The sex between us isn't part of her job and I'm not paying her for sex. Sex is dependent on her wanting sex and I'm lucky she enjoys me fucking her. But I can't just tell her I want sex I've to show my interest and she may or may not have sex with me.