She seemed oblivious to the fact that they had started sneaking around behind her back again, but Katie (Heather Tom) will reveal to Brooke (Katherine Kelly Lang) and Bill (Don Diamont) that she knows more than they think she does on The Bold and the Beautiful.

After talking to Brooke and spouting off more of her happy marriage act, Katie switched the topic to Brooke's secret new man in her life, and after a denial about it being Ridge (Thorsten Kaye) again, Katie shocked Brooke by insisting that it was Bill, and warning her not to deny it. Now, after Brooke deflects by claiming Katie is imagining things because she's drinking again, Katie will warn her sister that the betrayal is the thing that causes her to drink, and because she hasn't had it confirmed, she hasn't been doing so lately, and Brooke's immediately taking things there proves her guilt.

"I have this voice in my head telling me that something is going on here, and I have to make it go away, and it makes me want to drink," Katie says to Brooke in a preview clip for the Monday, June 27 episode.

Then, when Bill arrives home and sees the two locked in a heated confrontation, he will further confirm Katie's suspicions when he too writes things off as he and Brooke simply being concerns about her and her need to drink lately.

"There's nothing more important to your sister and me than your health and wellbeing," he says to her in the clip.

However, now that her suspicions are on high alert and she knows she won't get either one of them to confess, Katie will be more determined than ever to find proof they are having another affair behind her back. And with her investigation will come a big warning for Bill about what he will lose if she finds out he's done this to her yet again.

The Bold and the Beautiful airs Monday-Friday at 1:30 p.m. on CBS.

Tags: The Bold and the Beautiful CBS Soap Operas