Apparently I'm flirty and thats a problem, what do I do?

I’ve known this guy for almost eight months now and I’ve, unfortunately and involuntarily, fallen in love with him. We’ve talked about us and I know he likes me a lot and wants to be with me. He thinks I flirt though because I like to talk to people and I smile a lot when I do. I know when I’m single and not interested in ONE person I flirt a lot with guys that I like but not like teasing or anything really bad, an innocent flirting. But I want to stop because it bothers this guy. Any advice?