Sandra Bullock's children may have their disagreements, but they've got each other's backs at the end of the day

Sandra Bullock‘s children may have their disagreements, but they’ve got each other’s backs at the end of the day.

The actress stopped by the Ellen DeGeneres Show and opened up about the complex relationship between daughter Laila, 5½, and son Louis, 8.

“He wanted his sister and he knew she was his sister, but now there are moments when they want to kill each other,” the mom of two shared, noting that Laila is more likely to get irritated with her brother. Joked Bullock, “But I like that about her. I like that she’ll take a knife and cut a guy.”

Bullock explained that Louis is already a very protective big brother, but lying to his mom led to a guilty conscience during a recent incident.

Want all the latest pregnancy and birth announcements, plus celebrity mom blogs? Click here to get those and more in the PEOPLE Babies newsletter.

The Ellen DeGeneres Show
Credit: Michael Rozman/Warner Bros.

Sandra Bullock and Ellen DeGeneres

The Ellen DeGeneres Show
Credit: Michael Rozman/Warner Bros.

Sandra Bullock

“She did something — I won’t say what it was — but I tried to get it out of him because he’s very honest. And he was like, ‘She didn’t do it. Maybe she did this,’ and kept coming up with different scenarios,” the Oscar winner, 53, recalled. “Then we put him to bed and he’s like, ‘I don’t feel well. I have this tickling in my stomach. I have to tell you something.’ I said, ‘Okay, what it is?’ He goes, ‘I can’t tell you because I just like her so much.’ ”

Bullock confessed that she got the information out of Louis, joking that he “will be cut” now that Laila knows who tattled on her.

RELATED VIDEO: Sandra Bullock Challenges The Notion Of A ‘Traditional Family’

Bullock told DeGeneres her two kids are “very different but in this best way.”

The Ocean’s 8 star explained, “He can use some of what she’s got and she can use some of what he has. They balance each other out really sweetly.”

She recently described her little ones as having distinct personalities for InStyle‘s June 2018 issue.

“Lou is super sensitive. I call him my 78-year-old son. He’s like Shecky Greene, a Jewish Catskills comic. He’s wise and kind,” Bullock told the magazine. “I saw that when they handed him to me. There was a spiritual bigness to him. I was like, ‘I hope I don’t eff that up.’ ”

As for her daughter? The actress shared, “Laila is just unafraid. She’s a fighter, and that’s the reason she’s here today. She fought to keep her spirit intact. Oh my God, what she is going to accomplish. She’s going to bring some real change.”