Abby Newman and Arturo Rosales were destined to prove Nikki Newman's point to be true, thanks to his tryst with his brother's wife, Mia Rosales. Even though Nikki's prediction was rooted in jealousy, she wasn't wrong. The second affair between Arturo and Mia was the beginning of the end for the couple. This was a long time coming because Mia clearly wanted to be with Arturo. In an attempt to kill Abby to pave the way for her own agenda with him, Mia hit Abby (or so she thought) in the back of the head, forcing her to fall into a pool unconscious (via Soap Hub).
However, it wasn't Nikki but Lola, Arturo's sister. Regardless of the attack, the facts about the affair were eventually exposed, leading to a question about the paternity of Mia's unexpected pregnancy. In the meantime, Abby went berserk and destroyed Arturo's car in a fit of rage. She wasn't wrong, though, because Arturo was indeed the father of Mia's unborn child, forcing everyone involved to re-evaluate who was in a relationship with whom (via Soaps In Depth).
Abby's relationship with Arturo was over, leaving a far larger trail of heartache and destruction than the dissolution of his casual fling with Nikki. Abby was engaged to Arturo at the time of the revelation of his affair, so, naturally, she was distraught and quite uncertain about what the future had in store for her.
