Thought I'd share this for the minority that might be going through something similar. Don't do it. Let me know what you think. Thank you 
In my 40’s with a failed marriage, then a relationship ending more recently, I realise now that I gave you the wrong signals and this is entirely my fault.
But, I met my match in you - a good looking, older, charming and wealthy flirt. A real man. I don't deny that there is definitely chemistry there. I initiated contact with you - a married man. But being younger, pretty, sassy and available, you immediately swooped on to me on the off chance I could become your potential mistress, grooming me at every opportunity.
But for me it could work so perfectly where I am in my life right now, a ‘no strings’ arrangement. I seriously deliberated over it.
I don’t have to answer to anyone. Why should I care about morals? I am not doing anything wrong. I am single. I am not married to anyone. I can choose who I want to meet or sleep with - when and where. I am guilt-free. And there’s the thrill of the chase until I meet someone. Then I could drop you. Just as you would me if your Wife ever got a sniff of what you were up to.
And the appeal of the spoil. Selfishly, this could be very lucrative for me, you - my sugar daddy. Once a week sex in a 'posh' hotel, no ties, just you to purchase my loyalty and my secrecy. Perhaps some sexy lingerie, or a skimpy dress or earrings. A dirty weekend away. Or a meal at a posh restaurant and some expensive vino. Good company and the guarantee of sex. Perhaps you would fall in love with me and leave your Wife..
My Father was a serial adulterer. He moved in with the other woman when I was a kid. Then he came crawling back to my Mother. A few more flings over the years. I remember it all very well. In the end he abandoned her completely for another woman. A younger version – just like me. Unlike your Wife and your disclosure to me of having previous affairs in order to get you through your marriage, my Mother always knew. Over time she recognised the signs.
Perhaps your Wife does know. Whilst you are downstairs watching porn or chatting erotically to someone like me, she probably does, but she chooses to turn a blind eye to your behaviour. Perhaps she finds you repulsive because you are like a dog on heat all of the time. Have been for years. A randy, dirty old man. Perhaps all of that pestering over the years has put her off sex completely. Or perhaps she willingly has to oblige due to her marital commitment to you. Perhaps you have a great sex life but you are just so greedy.
I’ll admit, your charm, determination and the chase has been very addictive. I have been flattered by the attention you have given me during the day and whilst your Wife sleeps for the last couple of weeks.
But having now reflected the proposal on a more serious level, the ramifications, potential detriment and deceit, I have come to only one conclusion. I am ending this now before it gets out of hand.
Resistance is not futile. I have to respect your Wife and your Children. And I have to respect my Mother and Myself.