The conversation began when the host asked Cyrus if the "sexual side of you that we're seeing a lot of right now" would be something that she'd move on from in the near future.
The 20-year-old singer responded by saying she'd probably stop being so sexual when she turned 40, which, according to her, is when "people don't have sex anymore."
"I heard when you turn 40 things start to go a little less sexual," Cyrus began. "So probably around 40, around that time I heard that's when people don't have sex anymore, so I guess maybe around then."
Lauer jumped in at this point and asked Cyrus how old she thought he was.
"I gonna guess 40," she said with a smirk.
When the host announced he's actually 55 years old, Cyrus nodded and said that Lauer is "really definitely not sexual."