Dating European Guys, Split Bill or not?

Hi Everyone,

I am very confused because I am dating an European guy for the very first time.
I know most of western guys are very gentleman that after dinner when I offered to pay my part of dinner he declined.
So, I just let him do the gentleman part. However, he seemed unhappy about I really let him pay.
I don't understand what European guys thinking. I said I don't mind to pay my part, but he said no. So I let him.
Then he was unhappy. What should I do next time?
I know him online. That was our first meet. Could anyone who have experience to teach me how you do when handling payment?
I don't want to dispute on payment on such a beautiful date.
Is European Guys generally don't want to pay the bill? Should I insist on paying my part of dinner next time?
What about other countries like US and UK? Also the same?
Any advice is much appreciated.