“Those were very paranoid times, and let’s face it we didn’t welcome Yoko in the studio, because we thought it was guy thing,” he told Sirius XM radio during an interview with Howard Stern. “Actually, in the studio with us it was like ‘Uh, no, excuse me. Um, we’re working.’”
But he admitted that sometimes it wasn’t quite as serious, like when John Lennon was tripping on acid during a recording session.
“It was crazy because he had a little pill box, and he had his, sort of, little upper and his little downer and he thought he was taking his little upper... and we get along with the session, and he just comes over to me, and he whispers ‘I took the wrong pill.’ [I said] ‘What did you take?’ [He replied] ‘Acid.’ [I said] ‘OK well, let’s work around that then.”
But the time Ono entered the studio, tensions were especially high because the band was on the verge of splitting up, he explained.
“It was a heavy thing. Beatles breaking up. I’d known nothing else,” McCartney recalled. “We had this crazy success and suddenly, bingo, it was gone, like overnight. It was like OK what do we do now?”