2. Money will be an issue sooner or later
This problem may occur even from the simplest matter like gifts. First, he bought you a nice dress for your first date. Then he gave you a necklace on your third date. What if he buys you a car on your anniversary?
Should you take it or should you politely refuse?
Sooner or later, no matter what you decide, it will lead into a problem. Let say you take the car. You will feel like you owe him. Even when you brag about it to your friends, you may feel judged at some point.
Now let say you politely refuse. This may be insulting to your rich boyfriend, regardless what your reason is. There is simply no easy way out when it comes to money issues.