5SOS celebrate Valentine's Day in the studio with Sarah Hudson, Bonnie McKee and John Feldmann

Aussie pop-punkers 5 Seconds Of Summer celebrated Valentine's Day in creative style this year with a stint in the recording studio with some exciting names.

Songwriter Bonnie McKee, who is known for her work with Katy Perry ('California Gurls', 'Teenage Dream' and 'Last Friday Night'), posted a photograph to her official Instagram page on February 14 that shows the lads singing with Goldfinger's John Feldmann and singer-songwriter Sarah Hudson, who co-wrote Perry's 'Dark Horse'.

McKee captioned the image (which can be seen above left) with the following description: "Best #Valentine's day ever EVER w/ @5sos@michaelgclifford @calumhood @sarahhudsonxx@johnfeldy #5sos #MermaidBrigade."

The heartthrobs are currently working on material for their highly anticipated follow up album and have also been in writing sessions with Sum 41's Deryck Whibley, the Madden Brothers, and Marianas Trench's frontman.

Watch footage of the boys performing at Derp Con here: