"It was definitely one of those things where I thought, I didn't think I'd be talking about this joke more than once," Zac Hanson said during an interview the boys had with Australia's KIIS 1065.
"We were making koala jokes, and of course there's a chlamydia koala joke… and it was just a bad punchline," Taylor explained. "I was disappointed that nobody noticed the pun of 'ven-ear-eal disease," Zac said.
"Boys will be boys," Zac concluded. "We were just having a little fun, unfortunate, but whatever," Isaac added.
The brother's also shocked the hosts when the mentioned that fans have likely been singing their 1997 hit "MMMBop" wrong for 20 years now.
"Too many people put a 'wop' in there," Zac said. "What happens is people go to sing that song and they start making it up as if it's nonsense. But it's actually a repetitive part, it came from doo-wop songs. So it's a background part."
After singing a bit of the song, Zac also clarified what the title of the hit refers to, saying, "'MMMBop' represents a frame of time; 'In an MMMBop they're gone,' it says in the lyrics of the song. The whole song's about the fact that almost everything in your life will come and go very quickly. You've got to figure out what matters and grab onto those things."
Later in the show, the duo performed their own rendition of Harry Styles' 'Sign of the Times,' so it looks like his music doesn't remind them of any unpleasant STDs.