I just wanted everyone's opinion on this "relationship/friendship".

Summary:

I met a woman through a work friend and we hit it off from the day we started talking. I decided once I went home I'd add her, and risk looking like a stalker. We actually began getting really close and eventually we speak every day. She has an ex that she lives with, because they have children but he has someone else. They own the house together so they just decide to coexist, which I respect.

We first met on a park bench, had a chat and I walked her home. Hugged her in front of her ex to test whether he had feelings, and because I liked her. She then invited me over her place whilst he was working, stayed there for hours, helped her cook dinner, was playing with the kids. She told me that she's never seen the kids take to someone as quick, it was almost as soon as she open the door.

She's been sending tons of hearts, kisses, and appearing really affectionate in messages. She told me that I didn't need to go home so early, but I didn't want to invade during dinner time.

We've agreed to go and get lunch, she's excited for it and recently she's been facetiming me with the kids since apparently they keep asking about me.

I'm confused really. We've not really approached the "what is this" reaction, maybe we were just old enough to not need to. Are we dating? Is this romance? What happens when the kids become so attratched that I have to become a figure in their lives (I'll never replace their dad, I know.)

I'm just so confused.