Elvis Presley's brother on sex, drugs and the King of Rock and Roll in 1970s Las Vegas

always wanted brothers. His own identical twin, Jesse Garon Presley, was delivered 35 minutes stillborn before him.

In the years after, Elvis, raised as an only child, would often reference his late sibling he never knew and naturally was delighted to eventually be blessed with three new brothers.

When his father, Vernon, remarried in 1960 after the death of Gladys Presley two years prior, his new bride, Davana "Dee" Stanley, brought with her three sons from her previous marriage to a US Army sergeant.

Billy, Rick and David Stanley were just boys at first, growing up at Graceland, the private Tennessee mansion where the King resided with his extended family.

But it wouldn't be long before they were drawn into his entourage as personal assistants and bodyguards who would know the real Elvis and be by his side from the highest of highs to the lowest of lows.

David - who was in his early Twenties when he and the rest of the inner circle found Elvis' body on the bathroom floor upstairs at Graceland on August 16, 1977 - now lives and works at the Las Vegas hotel where the King performed his 636 sold-out shows from 1969-1976. An ambassador and historian for Westgate (formerly International Hotel), Express.co.uk recently sat down for an interview with the 68-year-old on the very stage where Elvis sang his heart out in his final years.

David was just four when the King of Rock and Roll became his brother, but it was a while before he cottoned on to who he really was. Speaking with the gravelly Southern twang of a man who has lived life, he shared: "When I met Elvis, I didn't have a clue what was going on... I walked in the house, and there was Elvis. He picked us up, my brothers and myself, and he welcomed us into his family. And you know, that felt good. People say, 'Wow, it had to be surreal.' I didn't love Elvis because he was a rock star. I loved Elvis because he said, 'Welcome' and loved me back.'

As David grew older he started to figure out that not everybody made movies and would spend his summer holidays on Hollywood sets, with Elvis shooting three films a year in the early 1960s. And by the time The King made his live music comeback 55 years ago at the International Hotel in Las Vegas, his youngest step-brother was 13 and wasn't really that interested in the opening night on July 31, 1969. That was until Elvis came out on stage and "blew the place apart."

David recalled: "Holy s***, this guy, okay, I get it now. That's when I became a quote 'Elvis fan, and begin to go, 'This guy, he's got it'. He and the family would then be in Las Vegas twice a year for each residency, which lasted a month at a time with no days off. David then turned 16 and the King of Rock and Roll asked him to drop out of high school to join his Memphis Mafia full time.

David, who got bullied at high school for being the King's brother, continued: "Elvis said, 'You don't need that. Just drop out of school. We'll get you a tutor.' My mother is going, 'No, no, not David too.' I was in high school one day, and the next day I was in the Madison Square Garden, and Elvis walked out on stage and 20,000 people went crazy. We did like, four or five shows that weekend at the garden."

The King taught him martial arts to channel his adolescent aggression before handing him a nine-millimeter Smith & Wesson at 18. He continued: "My job was very simple: You messed with my brother, you're going to be messing with the wrong guy. I either whip your ass or shoot you! Of course, I didn't have to do either... there was some crazy people out there, and there were sometimes I disarmed guys with knives...

When asked where he went to college, David would simply reply, "I went to EPU: Elvis Presley University", where things would only get wilder as the Vegas years wore on.

Looking back on the Las Vegas residencies, David reiterated that it was two shows a night, the second at midnight, for 30 days straight, twice a year.

He recalled: "February was mostly when the Hollywood people came. I mean, it was the adult crowd. August is when families and younger people came because they're out of school, out of college. I was 17, 18, 19, 20, 21, years old. I was at home on my feet. There were chicks everywhere! Listen folks, it was sex, drugs and rock and roll for me. I mean, I'm on the road with the biggest icon in the world. He's my brother, and there's plenty to do. So I had a lot of girls, got high and had my share of drinking and partying. [Now] when it was time to go to work I was always responsible. But hell, I was just an 18 year old kid; took advantage of it."

On the daily routine of living with Elvis on the top floor of the hotel and performing downstairs, he shared: "You'd do [the first] show, the second show, meet and greet, you know, celebrities or whoever... sometimes you would bring them upstairs. We'd party to 2,3,4, o'clock in the morning." However, the King himself was a much tamer than some might have imagined.

David, who is also author of My Brother Elvis: The Final Years and writer-director of the movie Protecting the King, added: "Elvis didn't party. Elvis didn't sit around and yahoo and drink and smoke. He didn't drink at all. He didn't smoke anything but cigars. Elvis would come out, meet and greet, talk to some people. If there was somebody interesting they'd get in a corner and talk all night. But mostly he'd just go to his room, and then the party would wind down. I'd go to bed 4 or 5 o'clock in the morning, get up at 3pm, upstairs at 330, Elvis was up at 4, and we'd do the same thing again for 30 days."

Asked if he got tired, he replied: "Well I was young, you know, I was 17, 18, 19, years old. [But] yes I was tired, and I was going, 'I don't see how Elvis does it'. Now we later found out about the medications that he took to go to sleep and to get up. I was always wondering why there was a doctor on tour and then that reared its ugly head as life went on."

My Brother Elvis: An Evening with David Stanley, which includes a tour of the backstage where The King performed, is held monthly at Westgate, Las Vegas, and tickets can be booked .