But I didn't tell him that because he would have come back.
'I thought: "I have to get over this because I can't be in a position where my existence relies on being with somebody." ' Particularly when that somebody was as mixed-up and difficult as John.
Outside the bedroom, their relationship seemed as frantically fruitful as ever.
They were both writing songs for new albums, and his latest lyrics abounded with adoring references to Yoko - 'I'm a fish and you're the sea'; 'Today I love you more than yesterday'; and 'Wherever you are, you are here'.
He talked enviously about a fellow British rock star who simply went to the bar at the Plaza Hotel each night and sat there until some young woman picked him up and they adjourned to a suite. They even discussed a candidate, guitarist David Spinozza. 'I wouldn't mind having sex with him myself.' So John flew to Los Angeles with May Pang, for what May thought would be a two-week stay.
A friend, former disc jockey Elliot Mintz, met them at the airport.
She didn't come on to him at all, but he just pulled her and went into the next room'.
As the grunts and groans of her husband having sex with another woman came through the wall, somebody put on a Bob Dylan record to try to drown the noise and spare Yoko's blushes 'but we heard it anyway'.
"' They agreed it would do their relationship no harm if John had other sexual partners. But I can't make it with a guy because I love women too much, and I'd have to fall in love with the guy and I don't think I can." ' Though eager to accept the sexual freedom Yoko was offering, John felt squeamish about doing anything under her nose in New York. He insisted that during their separation she must go out with other men so both of them would be equally guilty - and because he'd read that women who did not stay sexually active ran a higher risk of cancer.
Surprisingly, apart from that one drunken lapse at the election night party, he had never been unfaithful to Yoko and, even with her compliance, he had no idea how to go about it. Inseparable: With Yoko at a news conference in New York in 1973 'So then I suggested Los Angeles,' she remembers, 'and he just lit up.' The problem was that, since his earliest days as a Beatle, he had never travelled anywhere alone or had to fend for himself. Yoko looked over the various young females in their circle and chose May Pang, a 22-year-old Chinese American who worked as an assistant to both of them. He said he'd feel more comfortable if any affair she had was with a brother musician.
She tried to stay calm, and asked one of her assistants to go in with a flower for John and tell him she still loved him.
The assistant, understandably, refused, and Yoko was left with much to think about. She and John had sacrificed a lot to be together and it was worth it because they were so much in love.
But John's sexual restlessness could not be ignored - and one day Yoko decided to confront it.