A married woman that is flirting with you is taking her relationship with her husband for granted.
The relationship is monotonous.
She already knows what to expect from her hubby, and knows his daily routine better than he does.
By this point, he has lost his physical appeal in gaining weight, and has become lazy in no longer doing the pastimes he was once passionate about outside of work.
Grocery shopping together provides further insight into the household goods that someone likes and dislikes.
In the process of making this discovery, you learn whether there are commonalities in the household goods you both like.
This is actually extremely helpful in the early stages of a budding romance, as it gives the each of you a great deal of knowledge into what you find in common.
People frequently overlook the idea of grocery shopping as a date activity in the early stages of courtship.