Johnny Depp and Sir McCartney have become close friends since the actor agreed to appear in one of the singersr's music videos earlier this year.
The Beatles legend recruited the Pirates of the Caribbean hunk, along with actress Natalie Portman, to star in the promo for My Valentine, in which they are seen using sign language to translate the song's lyrics.
"Then suddenly they are all laughing at me because I'm in a waistcoat and I've done it too - subconsciously made a real effort. Everyone, Beatrice, all smartly dressed for our special guest"
McCartney has been acquainted with Depp for many years, but they only grew close after the video project, and the actor is now a regular visitor at the musician's home The rocker reveals his relatives are all extremely impressed with his "cool" new friend.
He tells Britain's The Sun newspaper, "It's cool. I had my daughter (Mary) and her husband and the kids staying there recently, and my little one (his youngest daughter) Beatrice. I said to them all, 'By the way, Johnny Depp is coming round'. They all perked up - 'Oh yeah?' I said, 'Yeah, he's coming round tomorrow'.
"That morning I come into breakfast and the first guy coming in is Mary's husband, and I say, 'You look very smart today'. Then Nancy (McCartney's wife) comes in, she's all smartened up - make-up, you know. Normally, everyone bowls in bleary-eyed.
"Then suddenly they are all laughing at me because I'm in a waistcoat and I've done it too - subconsciously made a real effort. Everyone, Beatrice, all smartly dressed for our special guest.
"Then Johnny comes in like he's an old cowboy. He just hung out, it was really nice. He brought me this funky little guitar as a gift. He's a really decent player".