The affair is the main reason why the witch-hunt began abigail very much wanted to be with John Proctor. However girls were to remain pure certainly, adultery was forbidden but for a young girl to have an affair with a married man would have been the most horrible crime of all. The punishment would be probably death for she has broken a rule that was very much important.
So the reader knows how the other characters thoughts and feeling toward the situation
The story is in the screenshot, I hope it helps you :)
