'Bold And The Beautiful' Spoilers: Liam Stuns Wyatt With The Truth

He's supposed to be in the midst of the happiest time of his life now that he and his wife are expecting a child together. So when Wyatt encounters his brother Liam and sees he is anything but happy, he will press him for answers, and wind up learning more than he ever expected as a result, on the Tuesday, Jan. 9 episode of "The Bold and the Beautiful."

Liam's (Scott Clifton) joy about becoming a parent with Steffy (Jacqueline MacInnes Wood) turned to horror on the CBS soap, after he learned of her paternity test and one-night stand with his father, Bill (Don Diamont). Since then, he has left Steffy and indicated their marriage is over, and also ceased all ties to his father as well. However, the only person who doesn't know what's going on—only that Liam is going to be a father—is his brother, Wyatt (Darin Brooks).

When Wyatt heads to the office and sees Liam packing his things to leave the company, Wyatt will joke around with him, but it will quickly become apparent that there is something more serious at work. Liam will insist he doesn't want to talk about it, but Wyatt won't let up until he tells him what's wrong. Finally, his persistence will cause Liam to explode, and when he does by telling Wyatt the truth, his brother will be stunned by the shocking revelation.

"He slept with Steffy!" Liam shouts in a preview clip.

Meanwhile, Steffy will receive another visit from Katie (Heather Tom), who has also since learned the truth. Steffy will still be despondent about what has happened, because Liam still refuses to come back home to her, and she will become worried that not only has Liam cast her aside, but that he will cast aside their child as well, no matter how much Katie reassures her that he will eventually come around when it comes to being a good father to his son or daughter.

"You're having his baby," Katie says. "He's not going to abandon that child. That's not who he is."

"I honestly don't know what Liam's going to do anymore," Steffy replies.

"The Bold and the Beautiful" airs weekdays at 1:30 p.m. EST on CBS.