The 36-year-old singer began the conversation by explaining a recent Instagram pic of himself dressed up as a woman while posing with The Bachelor Australia star, Nick Cummins.
"I feel like you love a good dress up," said Henderson, which prompted Sandilands to ask Sebastian if he's ever dressed up in the bedroom for his wife, Jules Sebastian, just "to keep things sexy."
"No I haven't, but we were actually talking about it recently," the dad-of-two answered. "About just doing a scenario like they did on Modern Family, where we just meet each other at a bar and I'm not Guy Sebastian -- I'm just some bloke and we just sort of get into character.
"Seriously, I need to do something, I've been away for ages now and I was on tour before that, so the fire's out of it," said Sebastian, who was calling from LA. "We need to stoke the fire in our relationship. I've been away for too long."
However, the idea didn’t exactly go down well with Guy’s wife, Jules.
"There's never any time for anything that's remotely kinky, and even when I try to send some kinky stuff, it always gets shut down," he admitted. "As a bloke, you're sitting there going, 'I'm actually a bit nervous that she'll take the piss out of me.' And you build up all that courage and then they shut you down. It's horrible.
"I mean, what I was asking before was absolutely filthy though, and it does sound painful when I think about it."