Yep. If you are more than a fling? You sound like you are building some kind of open model
with her and figuring out what the boundaries will be.
Are those limits acceptable to you? No overnights and no going out of town at this time?
If you don't LIKE being a secret, could tell your dating partner this, and your metamour (the husband.) Could tell them you expect to be negotiating when you will come "out" to her children, family, friends, etc. You don't want to be hidden.
Could meet the husband and see how it unfolds and you all negotiate "being poly" together. If it is not sounding like a runner after all? Could end it before it gets deeper and just be friends.
You were straight up to your new dating partner/not quite GF about asking the other woman out. I assume you were just as straight up with the potential date that you have another dating partner.
You could be reassuring and supportive as she works through her jealousy stuff. But you also don't have to promise things you are not willing/able to promise her. If you are ready, willing, and able, great. But this is a newish thing here. Could not rush.
You haven't lied or promised anyone exclusive/commitment type stuff at this time -- you don't have to unless you want to WHEN you want to.
Life is short. Much too short to live it less than authentically, ethically, and honestly. Play ball. Play well.