Dina Mergeron dropped a bombshell this week on "The Young and the Restless." In one of her more lucid moments, she told Abby that John Abbot is not Jack's Biological Father. Dina went on to tell her granddaughter of the many affairs that she engaged in while married to John but could not recall the name of the man she claims is Jack's dad. Victor Newman is the first person to come to mind but with Lori and Leslie Brookes having returned to Genoa City for the Walnut Grove centennial, Stuart Brookes also comes to mind.

Don’t miss on the latest updates Follow the TV Shows Channel

Dina's 'Y&R' history is being rewritten

The history of Dina Mergeron is being rewritten right in front of longtime viewers [VIDEO] of "The Young and the Restless." It began this week when Abby decided to preserve her grandmother's memories.

While doing a video interview, Dina said she went skinny dipping with Katherine Chancellor and John Abbot when they were teens. She also mentioned Jill's affair with Stuart Brookes.

Dina also spoke about multiple times she cheated on John when they were married, and said that Jack was the result of one of her indiscretions. She later had Abby driver her to the Stardust motel where she pulled out a room key she has kept for all these decades.

Fans want to know who Jack's father is

It was recently revealed that Ashley's biological father was Brent Davis, but now to suggest that even Jack is not John's son is a stretch. This would leave only Tracy and Billy as blood Abbots [VIDEO] who have the right to run Jabot. "Y&R" fans want to know the truth and Abby has decided to get the ball rolling.

On Wednesday Abby told he mother they should have a DNA test done, and that would at least prove whether or not John Abbot is Jack's biological father. If the results indicate he is not, then the next step will be to determine which one of Dina's paramours is Jack's dad.

Dina's memory is questionable regarding Jack's father

Until this week there had never been a question that Jack Abbot was John's son and if he is not it will be explosive. Now that Dina is dealing with Alzheimer's disease, Ashley believes her mother is mistaken. Abby, however, wants to pursue the truth and a DNA test would do just that. Many longtime "Y&R" fans believe in a strange twist of fate that Victor will be the biological dad of his sworn enemy.

This would create chaos and have the Abbot and Newman families double related. Abby would be Jack's niece and half-sister, Victoria would be his half-sister and former sister-in-law, and Ashley would be his half-sister and also his former mother-in-law. Stay tuned to "The Young and the Restless" weekday afternoons at 12:30 PM EST on CBS.