Why is this man offering us cash?

I don't think you need anyone to answer this question - you know the answer yourself. An old man offering cash to a pretty young girl? Asking to kiss you goobye. Vowing to get back into shape and look like he did in the 70's. Those are not comments made in a regular conversation with someone you are just socially polite to. You need to get rid of this guy fast. Start jogging a different route. If you run into him and feel forced to say hello, say it but keep moving. Your friendliness has been misunderstood by him as "interest" on your part and that's why he keeps taking things a step further and further. I'm like you - I like to believe in the inherent goodness in everyone, but the unfortunate truth is that there are creeps and perverts out there using various methods to entice people into their lives. He may indeed be a very nice man who is just lonely and likes someone to converse with, EXCEPT for the point that he is escalating his interest in you by asking for a kiss, offering you money - what do you think will be the next thing? The fact that you "feel he is getting way too much happiness by being around me" says that your intuition has already kicked in and you know damn well that you are getting in over your head with this. DO NOT take any cash from this man. If he aults you later and you end up in court, the judge will look very poorly at the fact that you took money from him. The old man can use as his defense that by taking cash he umed you were agreeing to go further with him. If your sister sells the business she will get her commission - that money is legal. Any cash you take out of his hand is questionable.