Gene Simmons “never thought” KISS would last more than “a few years”.

The 72-year-old rock star – who co-founded the band back in 1973 and is now on one final tour alongside Eric Singer, Tommy Thayer and Paul Stanley – claimed that it was “unbelievable” that they are approaching their 50th anniversary.

He said: “We start playing the outdoor stadiums of South America, literally within two weeks, and continue on to Europe and Australia and eventually North America, Japan, all that stuff. Mexico. And this is going to be the last tour. We’re done. We’re approaching 50 years of doing this, which is unbelievable because we never thought we’d last more than a few years.”

Gene went on to explain that he and his fellow ‘Black Diamond’ rockers have decided to call it a day because the “last thing” they want to do is “stay in the ring too long.”

He told Entertainment Tonight: “It’s the right time to get out of the ring. The last thing that you want to do is be a guy that stays in the ring too long and gets his a** beat. Get out of the ring when you’re a champion. ”

Gene went on to claim that KISS – who are known for their outlandish shows involving stunts and flamboyant costumes – are the “hardest working band” out there and joked that pop star Beyoncé would “pass out in half an hour” if she were to don their heavy costumes.

He added: “You got to understand — we love Jagger and Bruno Mars and Bono and anybody else, they’re all great, but if you put those guys – Beyoncé, put Beyoncé in my outfit with seven to eight-inch platform heels, dragon boots that each weigh as much as a bowling ball, the entire outfit, studs, leather and armor is about 40 pounds. The guitar and the studs is 12 pounds by itself. Then, you got to spit fire, fly through the air and do that for two hours. They would pass out within a half hour!”