What counts as cheating?

I am currently with my boyfriend for 10 months. He's a really nice guy, but I would say he falls towards a more controlling side. For example, I used to have lots of guy friends before we got together. I really don't see anything wrong with having many guy friends because I've known most of them for years, and I never was attracted to any of them. After we got together, I could only keep in touch with them secretly via text because my boyfriend will get mad and we will start quarrelling. I usually don't like people controlling what I do, and i dropped some of my exes because they controlled me, especially my friend circle. However, I didn't drop my current boyfriend. Other than that, he is caring and nice. 
A week ago, I met a new guy friend and we got along pretty well. We could talk about anything and everything, and he confessed to me that he actually likes me. I rejected him upfront because I'm in a relationship, but he says he doesn't mind waiting and hopes that I will reconsider my decision slowly. We talk a lot. My boyfriend and I are also quarrelling a lot this month due to exam stress. 
My boyfriend doesn't know about this, but I didn't get into a relationship with the guy friend but I admit I'm kinda attracted to him. Am I wrong? What should I do? The guy friend tried flirting with me and stuffs like that but I brushed him off every time. I'm really confused with my own feelings right now and it's the first time I'm actually feeling this way..