Naomi Watts found it "more romantic" when Billy Crudup told her he had grey pubic hair than when he proposed to her

In an extract from her book 'Dare I Say It: Everything I Wish I'd Known about Menopause' published by The Times magazine , she wrote: "Before long, our feelings were undeniable: we were falling in love.

"He added that he could hardly be surprised; we were the same age, after all: 'Hey, if it makes you feel better, I've got grey hairs on my balls.' Swoon.

"Reader, that did make me feel better. Those to date remain the most romantic words I've ever heard, on screen or off, and that includes the script of every movie I've been in, and even this same man's very loving marriage proposal, which came seven years later."

Naomi - who has Sasha, 17, and Kai, 16, with former partner Liev Schreiber - admitted falling for Billy, also 56, in 2017 took her by surprise because she had started work on 'Gypsy' in "no mood for romance or flirting.

She wrote: "I didn't know for the longest time that my co-star on a TV show was going to be the person I belonged with.

"There were no signals going off. I was in no mood for romance or flirting. I planned to hold myself together for my kids and keep my head down at work.

"Like so many women my age, I found my libido wasn't what it had been in my 20s. Maybe one day I'd find love again, but I knew I wouldn't be looking for it for the foreseeable future - and certainly not at work...

"Billy and I chatted on set during lighting changes and I'd have said we were friendly. But for a very long time, that was as far as it went.

"I was so closed off to love that in the months and months of shooting, even after we'd simulated sex on screen many times, dry-humping each other to the point of exhaustion, I hadn't given romance with him a thought.

"Then one day during a sex scene, he spontaneously flung a pillow across the room while ravishing me with such passion that I blushed and broke character. 'Oh! Why, hello, sailor,' I thought to myself, and as me, not as the woman I was playing. Then, 'Wait, that felt like... something.' "