Scene 2 How does the poker night contribute to what happens between Stanley and Stella?

I am not sure what happens between Stanley and Stella you mean, but Stella plans to take Blanche out on the town to take her away from the crudeness of Stanley and his poker buddies.  At one point, Stanley angers Stella because he assumes Blanche has defrauded them out of their rightful inheritance from Belle Reve.  Ultimately, Stella goes to the store to get Blanche some drugs and Stanley discovers indeed that Belle Reve was lost because of many mistakes of the owners in the past.