This is quite hard to explain, so it may be quite long. But I'll just start with the basics, one of my friends has like me ever since year 8 and for 4 years now I've told him straight that I'm not interested and its all been fine. But at the beginning of the year everybody knew he was speaking to another girl, so I figured harmless flirting couldn't do any harm, now that he's not interested. But anyway, it turned out he still liked me and the other girl was a cover, from then until know I've told him numerous amount of times that I don't want a relationship but I may have led him on a bit in the process, I suppose. Anyway, recently I've been speaking to his best friend every day for over a month, he's moving to Dubai at the end of summer and I've only just realised that I actually really like him, and I think I'm falling for him hard.
We have our end of year prom next Friday and I really want to try and get with the guy who's moving to Dubai, but I don't know what to do about his best friend who thinks that I like him and that something is going to happen. I really don't like him, but I really like his best friend.
WHAT DO I DO?? :( please help!

Tell him the truth. That you are just NOT interested. Being honest is always the best policy. Other then weaving untruths to cover up.

Tell him the truth. But you know flirting with him know how he felt about you was low. You don't play games with people like that.