The loved-up couple took the tube to Rod's big performance at London's O2 Arena.
Olivia Newton-John has announced plans for a short residency in Las Vegas later this year.
The singer will play 45 dates as part of her ‘Summer Nights’ headline residency in the Donny and Marie Showroom at The Flamingo.
The first show is set to take place on April 8 and the concert series will run through the summer.
The setlist will include performances of Grease classics 'Hopelessly Devoted To You' and 'You're The One That I Want', as well as Newton-John's numerous solo hits, reports Billboard.
Tickets for Newton-John's Summer Nights go on sale from Friday, February 7.
Watch the music video for Olivia Newton-John's ‘Hopelessly Devoted To You’ below: