Kaley Cuoco Teases 'Surprises' in Store for Tom Pelphrey's First Father's Day (Exclusive)

Kaley Cuoco has some surprises up her sleeve for Tom Pelphrey's first Father's Day.

ET spoke with the actress on Thursday at the red carpet premiere of her new TV series, Based on a True Story, at the Pacific Design Center in West Hollywood, California, where she was tight-lipped on what he can expect on the upcoming holiday -- but shared that it will be exciting!

"I have a couple little surprises for him," she admitted slyly. "I'm very excited about it."

Cuoco stopped short of revealing her plans, sharing that "he would watch ET" and it would spoil the moment.

Last month, Cuoco enjoyed her very first Mother's Day since welcoming daughter Matilda in March. The memorable day was "as sweet as it gets" for the 37-year-old, who was treated to brunch and family time while Pelphrey flew in to be present for the occasion.

During the filming of her new series, Based on a True Story, Cuoco was pregnant with Matilda, and she shared memories of what it was like on set.

"We literally would go to playback to see if we could see [her kicking], because it was so intense!" Cuoco recalled. "I was like, 'How did you not see that?' You could see it in person! It was crazy."

"I'm totally ready to dive in for a season 2," Cuoco continued. "I had the time of my life on this show, with the best people, it couldn't have been more fun."

"I just hope I'm not pregnant next season again, that's all," she added. "But you know."

Cuoco also gushed about receiving high praise from Pelphrey for the project.

"I wish he was here, you know, he loves this show. I don't know if he's biased 'cause he, like, really likes me, but we watched all the episodes and he was like, 'Are there more?' He wanted more," she said. "He's like, 'It's so much fun.' So he loved it. That always makes you feel good when your partner is like, 'Yes, yes, yes!'"

Cuoco's co-stars joked about their own early interactions with Matilda on the set.

"We were doing a scene together and her sweet baby kicked so hard in the middle of the scene that we both like, it's like we both screamed and stood back," Ever Carradine told ET, joking that Matilda "was like, 'I'm in the show, too! Don't forget about me!'"

Liana Liberato shared that the cast made something of a game out of attempting to guess Cuoco's baby name, which she kept "under lock and key."

"We tried to guess her name through kicks," she joked. "We were like, 'If your name has two syllables, kick twice.'"

The process almost proved fruitful, with Liberato and co-star Priscilla Quintana nearly making a correct guess.

"I think Priscilla and I got pretty close at one point and Kaley kind of gave us a look, and we're like, 'We're close!'" she said. "I wish I could remember [the name]. I think it was something with an 'M' and it had three syllables."

Based on a True Story debuts June 8 on Peacock.

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