The Aussie rocker, 23, has proudly posted the pic to his Instagram stories.
Cyrus, 27, is pictured naked and grinning from beneath the bubbles, a gold chain around her neck, her hair up. Also posted on Simpson’s Instagram stories were selfies of the couple together in what appeared to be bed.
The pics were posted just one day after Cyrus posted video of the couple preparing for a pilates session, wearing tight and revealing gym clothing.
Cyrus filmed herself through a mirror while wearing revealingly rolled-up skimpy gym shorts and a workout bra.
The video was captioned, “We have a different idea of ‘werking out’.”
The couple have been dating since last October and Cyrus described Simpson as her “best friend in the entire world”.
Cyrus appears to be recovering well from her split with ex-husband Liam Hemsworth.
She recently posted on Instagram her secret to moving on: “Star dating your best friend ASAP”.
She also posted a racy pic of herself reaching into Cody Simpson’s pants.
It comes as Liam Hemsworth, 30, was reported by People magazine to be seen “getting serious” with new girlfriend, Australian model Gabriella Brooks, 21.
Hemsworth was photographed introducing Brooks to his family and enjoying a meal together in Byron Bay.