How to prove that I'm not flirting?

I've been trying to court this girl. I love her and she loves me too. But the problem of us not being together is because I'm charismatic and a lot of girls talk to me. I've used to flirt with every girl I can, but I've kinda changed 5months before I knew her. She doesn't trust me because of this, how can I prove to her that I'm not flirting anymore and want to walk the endless road with her holding my hand ?
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+1 y
Btw I had a girlfriend during that time.
How to prove that I'm not flirting?
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