In The Crucible, what is the deal with John Proctor and Abigail in Act One?

An important 'deal' between the two of them is John's wife
Elizabeth. They even refer to her in this scene. Abigail sees John as a stud. She thinks
he is going to waste because his wife is not that hot. Abigail describes her as "sickly"
whether that means in looks, attitude, or actually her health, we don't
know.

As John defends Elizabeth, Abigail defends herself by
noting that Elizabeth is talking trash about Abigail in the
town.

John seems to want to be a man that does the right
thing which includes being loyal to his wife now even though he made a mistake in the
past. Abigail thinks his marriage is a lost cause anyway, so why not have fun? This
incident between the two of them triggers much of what happens the rest of the play.
Enjoy the drama.