Should I break up with him?

Well, your profile says you're under 18. At that point in life, it's really hard to see yourself staying with a guy that you really don't find as "fun" as you used to. In other words, you guys have gotten used to each other. You can't expect your relationships to be roses and honey forever. If you feel like you can make something out of the relationship, then stay. If you feel like both of you are bored and there's really nothing more to stay for then leave. It's a matter of personal preference, and getting a "feel" for how it's going to end up. However, I suggest staying if both of you still really enjoy being together, even if he isn't uber romantic every chance he gets. Think of it like this: Now he gets to surprise you with romantic things instead of you getting used to them all the time ^_^ Who doesn't like surprises?

I think you need to explain the problem more fully. If it's just that you guys aren't having as much fun, maybe you just need to find some new things to do together. If your relationship has become too repetitive, then you're going to get bored.