Juno and the Paycock Lesson Plan

Why is Jack's reaction to the news of Mary's pregnancy so out of character?

There are several reasons to be surprised by Jack's threats of violence against Mary for being pregnant. First, for all his bluster, Jack has not threatened violence against anyone so far, no matter who they are. Second, Jack has not taken much note of Mary throughout the play and, by Juno's account, for much of her life previous to this time. Jack's reaction could be classic msogynistic bullying, in that he perceives Mary to be weaker, physically and emotionally, than the men who have actually done him wrong, and thus he regards her as a better target for his frustrations.

Given how savvy...