So these 2 best friends are going to enter a contest to win concert tickets(of whom they both love ever since childhood), but it turns out only 1 can win, so one of the best friends entered the contest without the other knowing.

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So I just need help with coming up with a backstory that will make the conflict between the two (when the other friend finds out) even stronger.
Or just give me ideas on how to make my story better. Thanks!!!

Since there's little chance of either girl winning the contest, I suggest you find another story line.