Evening,
So while I was travelling in Romania I chanced upon a Romanian HB9. I was looking for some info in a German Cultural centre, I approached her in a group and moved her away from it.
We chatted in German (turns out she likes it more than Romanian) and she invited me to a party their student club was throwing.
I was seeing other Romanian girl at that time (they know each other) and so I hadnt gone to the party.
She invited me to another party, which I cancelled again.
When I texted her two weeks later to see if she is still in town, she was away already but texted me that she wants to "see me unconditionally" the next time I am in Romania, which will be in October.

How do I keep the interest going for two months, if it is possible at all?

I managed to keep in contact with a girl for just over 2 months. The initial interaction was really good but only ended in a number close. We chatted via text and finally met up for a day two when I got back home. I would recommend taking it easy and only message like once a week to keep in contact.

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You can do anything and have anything, the only thing stopping you is you.

Once a week is fine, and make sure you are the one to end the communication each time. Leave her wanting more.