He thought they were real.
It means the woman has lost a primary erogenous zone. They feel like a thing stuck to them, like a pair of shoes. I suspect it’s why women with implants are not shy (generally speaking) about exposing them. They don’t really see it as part of their body any more.
I once heard a Playboy photographer promoting his book.
Pam Anderson was mentioned, and the photog pointed out that many of the top centerfold models would go out and get implants, for some unfathomable reason, AFTER they were centerfold of the year, aka “most beautiful”.
He said Pammy’s first “enhancement” was pretty bad, and had to be redone.