Why am I always the back-up plan?

StoryOfMyLIfe
Il always find myself liking a guy and getting close with them, but I'll always be the backup plan or they'll ask someone else out instead of me. They'll tell me they have feelings for me but choose someone else. I'll start out as a possible relationship but turn into a "good friend"

So this is the question. What am I doing wrong? Why am I always in this position and how do I get tagged as just friend? How do I get out?
Why am I always the back-up plan?
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