How do I ask a girl about a past relationship without invading her privacy?

well i know that she dated this guy in the past or they knew each other and spent some time together. but not sure who he is to her and not sure if he's still in her life or not , i've talked to her a lot at her work but never like discussed this specific thing with her

i've always kind of felt that she really liked me which was why i was left so confused about this other guy and who he was to her , she never really acted like she had a boyfriend or even a guy in her life at all when i was around her

just left confused really and i don't want her to feel like i'm invading her privacy by bringing it up , its possible he is long gone even if they did really date and she just wants to spend time with me now instead

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6 h
note don't have an issue that she had a past relationship , mean everyone dated or knew someone in the past , just confused who he is to her and if he's is really out of her life or not , that is sort of the issue , has never been any clarity
How do I ask a girl about a past relationship without invading her privacy?
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