Kathy Hilton keeps naked pictures of herself in a "vault in a bank".

The 65-year-old socialite has insisted she has never sent any X-rated snaps via text message, but she and businessman husband Richard Hilton, 69, have some safely stored away.

On Tuesday's (10.12.24) episode of 'The Real Housewives of Beverly Hills', Kathy was asked by her half-sister, Kyle Richards, 55, if she's ever sexted her spouse.

Kathy replied: "We have a couple in the safe in the bank.

"Caesars Palace in Las Vegas, they have those beds with the big mirror. Seriously, it's so sexy."

A shocked Kyle quipped: "Who puts their nude photos in a vault at the bank? I'm just picturing Kathy naked with, like, fuzzy socks and a hat on."

Kathy - who has daughters Paris Hilton, 43, and Nicky Hilton, 41, and sons Barron Hilton, 35, and Conrad Hilton, 30, with Richard - recently shared the secrets to keeping their marriage alive after recently celebrating their 45th wedding anniversary.

The couple have been married since 1979 and just days after reaching the milestone, Kathy admitted that the "key" to their success is keeping the "right influences" around them.

Kathy also revealed they've never spent more than two weeks away from each other.

She told People: "We're best friends. And, I was just saying to someone, getting married so young like that -- I was 19 and he was 23 -- [the key is] just keeping the right people around you, the right influences and being around other couples who are happy [and] have the same values as you. We have not been away from each other for two weeks in [all our years] of marriage."

The reality star noted that the pair of them don't go to bed on an argument and always try to "keep a little mystery" in their marriage to keep the spark alive.

She said: "I don't think you go to bed without saying, 'I love you,' and giving each other a kiss and never in a fight or anything. If you have had a disagreement, you always make up before you go to sleep and keep a little mystery and always keep it exciting and fun."