Don Diamont's "The Young and the Restless" character Brad Carlton made a cameo on "The Bold and the Beautiful" in 1993, and in 2021 he brought Bill Spencer to "Y&R." During the appearance, the audience had to suspend its disbelief while the characters pretended that Bill looked nothing like their old friend, Brad.

Here's how his cameo came about: Summer Newman was digging up dirt on Sally Spectra, who had just moved from "B&B's'" fictional version of Los Angeles to "Y&R's" Genoa City, and Bill had the information she needed to make Sally's life miserable (via Michael Fairman TV).

"I had not ever considered that I would be part of a crossover, just because my character was so well-defined at Y&R," Diamont told Soap Opera Digest. "It wasn't like I was on for three months. I had never even considered that possibility, so it just kind of took me by surprise when they asked."

Of course, it wasn't long before Bill was back in LA and Diamont was back on "B&B," a soap he has called home for more than a dozen years.