Mr.Doran in 'The Boarding House' marries Polly due to social pressure whereas shoba in 'A Temporary Matter' walks out of marraige due to the same social pressure.
The reason for Doran to unwillingly decide to marry Polly despite her wrong grammer, vulgar behaviour, unfavourable family is the social pressure. But in Temporary Matter by Jumpa Lahiri, the couple decides to divorce only because of giving priority to a trivival matter. Lack of communication is the reason for that, it's not because of any moral paralysis or social pressure but more about their own misunderstandings and misconceotions. Therefore, according to my knowledge of the both texts the reasons for the two incidents does not resemble that much.
In The Boarding House Mr. Doran and polly married due to pressur of Polly's mother Mrs.Moony and Mr. Doran married Polly to keep his reputation.but in A Temporary Matter Shoba and Shukumar walks out with thier marriage due to the missunderstanding among them