I just found out that the guy that I was seeing had a girlfriend. Why did he only see me as a side chick?

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Before anyone says anything, I ghosted and blocked him three weeks ago. I’m just left wondering: Why was I side chick material? What does his girlfriend have that I clearly don’t have?
I just found out that the guy that I was seeing had a girlfriend. Why did he only see me as a side chick?
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