Olivia Newton-John and John Travolta certainly had amazing chemistry as Sandy Olsson and Danny Zuko in Grease, but that doesn’t mean they were lovebirds in real life.

In a new interview, Olivia, 69, revealed why she never dated the 64-year-old famed actor since every fan of the hit 1978 film thought they’d be the most perfect pair in real life.

“We were both with other people when we were filming and I think, respectfully, it just didn’t happen,” she shared with Mia Freedman on the No Filter podcast, adding that she would describe their bond as “sisterly.”

olivia newton-john and john travolta
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Olivia continued, “I think it was good, because I think it kept the tension there and the chemistry. It might have been a real disaster had we decided to date or we had a falling out or something. So I think it was just as well that it didn’t happen. But we’re still great friends.”

But just because they didn’t date doesn’t mean John didn’t have a crush on the blonde beauty during filming back then. In fact, their co-star Didi Conn (better known as Frenchie!) revealed that was very much the case. “Oh yeah, [he did like her]. What was so much fun was that most of us were older than the characters we were playing so we just stayed in character all day long. So there was an ongoing improvisation happening so the flirting… was fine. It was the context of the characters and the storyline,” she once confessed.

However today, the two are happily married — Olivia to John Easterling and John to Kelly Preston. And since they’re all such good friends, the actress has shared how supportive John has been through her current breast cancer battle. “He’s been wonderful. He calls and checks up on me,” she once said. “He came to one of my shows — right before this happened, actually, right before my diagnosis. I saw him and I was hobbling around the dinner table because I was having trouble sitting down. And he was concerned.”

olivia newton-john and john travolta
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Probably because John respects her so much. “She’s always been an incredible human being and an inspiration to millions,” he has said. “I know her so well. If we all put our intentions for her to get through this, she will feel it and it will support her. We love her and she loves us.” We love how close they are!