Thanks so much LovingRadiance, AnnabelMore, ThatGirlInGray, Vixtoria for your thoughts and advices.
So the consensus is that I should be meeting the husband. Im having cold feet just thinking of that. Anyhow, if that will give me peace of mind and help minimize any future trouble, then it may be worth the try. And I feel she is worth all the hassle.
But to tell you guys frankly, when I told her that my ideal relationship is long term and family-like, and she indicated that it may be possible, it did not occur to me that it might be in the context (poly context) of your experiences of being married and having a bf/life partner (esp. that of Vixtoria's). At the back of my mind, I rejoiced and was thinking that she might want me to replace her husband as his primary partner (or she was anticipating a separation) at some point in time (i apologize... i know this kind of thinking is a polyamory taboo...remember my mindset is originally mono). And thus, my reluctance to the possibility of meeting her husband.
Lastly, if I get to meet both of them, will I not be giving an impression that I want to have a relationship with both of them, like a triad? Im a straight guy, and has no plans of a 3-way relationship. No idea what the sexual orientation of her husband could be