Treat the man honestly. After all, this is often not enough provided to gentlemen. They are accustomed to the fact that all of them try to cheat and get them something. So if you're interested in him, his problems, his Outlook on life, he'll appreciate it. It is not necessary to simulate strong feelings, he recognises a lie very quickly.
Never ask for anything, especially if your request involves obtaining certain material benefits for you. A man may think that he is on his own you don't need. As a rule, with them all trying to get at least something, so any request on a subconscious level, to hurt their pride, and even the slightest query or request will cause a negative reaction. So if you need to hammer a nail, do it better themselves.
If a man offers you a gift, keep it. Take and show how you are happy with this sign of attention. If a man asks what to get, choose inexpensive gifts. Otherwise, he may feel that you are communicating with him for the money. Choose small gifts, tickets to the theatre or cinema, flowers. Then man will understand that you treat him sincerely.
Never give a man cause for jealousy. Wealthy personages, that feeling may result in unpredictable actions. They can end the relationship at the slightest hint of infidelity.
Be interested in his Affairs. Ask about how his day was, what he was having problems and that was interesting. Try with him to chat while demonstrating your intelligence. Wealthy men like smart people with whom you can just talk.
But otherwise behave with him as with any other man. Don't live only for him, the stronger sex is not appreciated. Always have an opinion, think about their needs. Of course, this does not mean that you should behave selfishly. Try to build such a scheme of communication in which will be comfortable to you and him.