Me the Other Boyfriend, or Her the Mistress

I’m recently separated and have been seeing this girl on and off for two weeks. She has a boyfriend. I fetched her from the airport the other night, she said she missed me, and she hugged and kissed me on the cheek. While together, we were as per usual giggling, laughing and teasing.

I didn’t know how we got into discussing this but she asked me what I wanted out of what we had: did I want myself to be her “other boyfriend”, or did I want her to be my mistress. She said she’s not comfortable thinking that people might get hurt. She said she might need time to think where I stand.

But the fun and teasing continued after that. I’d normally kiss her lips before dropping her off and she would normally text me not to do that again, but it still happens every time anyway. That night we kissed with her eyes closed, longer and passionately, then bade goodbye.
I did not contact her since then thinking she needed space. It’s been two days that I haven’t heard from her. I know this is messed up but please advise.