In 2009, Donna Logan became friends with Bill Spencer Jr. (Don Diamont), who was dating her sister Katie Logan (Heather Tom). Around this time, Justin Barber (Aaron D. Spears) was introduced to the scene as executive vice president of mergers and acquisitions at Bill’s company, Spencer Publications, and attempted to help his boss acquire Forrester Creations (via Soap Central).
Justin and Donna inevitably bumped into each other, both shocked to see the other. It turned out that the two had been high school sweethearts and Justin’s heart was broken when Donna suddenly left him and moved to Europe.
Donna confided in Katie that Justin was the father of her son Marcus Forrester, but according to Soaps In Depth, neither man knew about the other. However, it wasn’t long before Justin saw Donna with Marcus and put two and two together. Furious that she had kept Marcus’ existence from him, he demanded that he be allowed to meet his son.
Marcus was happy to form a relationship with his biological father and even considered taking his surname, Barber, before deciding to remain Forrester.
https://www.thelist.com/961061/who-fathered-donna-logans-son-on-the-bold-and-the-beautiful/ Who fathered Donna Logan’s son ‘The Bold And The Beautiful’?