I am accidentally head over heels for this person. I started talking to Grace about two weeks ago because she reached out to me on okcupid and we hit it off. I am single and she has a wife I have not met and will probably not have a romantic relationship with. We recently went on a date and had an absolute blast, we had a ton of chemistry, we lined up on so much, it was like we were resonating. I asked if I could be her girlfriend at the end of the date and she said yes!

But... like I really want to take this seriously. She's made some jokes and said some things that make me feel like our relationship has an implied "cap" to it but I don't know if that's just my typical worrying self. I'm dating people right now with the primary goal of finding someone to settle down and nest with one day. I'm comfortable with casual situations but this feels very un-casual or at least my feelings are feeling that ugh I dunno. I don't care that she's married, I'm just concerned with how far I can take my relationship with Grace. Like how can I possibly ask "hey I need to know if I can just let my heart want you as much as I want it to want you" without seeming like I'm asking how she feels about marrying me or me moving in or something? I do not want to scare her off she's lovely and I'm lonely. I don't want to lose my connection and the potential of deepening connection with her but also I don't know if I can continue if I'm just "on the side" or a fun fling. I don't even want to tell her that I love her or anything I just don't know how to ask about how serious this is without being weird!!! I feel like if we were in a "monogamous" situation or where if we were both single I wouldn't have to clarify like this as much. I'm like trying to build these concepts from the ground up while trying to get a relationship up in the air and it's so stressful please help 😭

tl;dr how can I politely and tactfully ask how serious a budding relationship is without scaring someone off and in the midst of feelings?