Tom Ellis, Debbie Gibson sing duet ahead of 'Lucifer' Season 5 premiere

Tom Ellis and Debbie Gibson released a video where they sing their own version of Lady Gaga's "Shallow" to promote the release of "Lucifer" Season 5.

The "Lucifer" star took to his Instagram to share a video of his duet with the "Lost In Your Eyes" singer. In it, Ellis is playing the guitar while he sings along with Gibson, who belted out her signature high notes.

"Oh you know, just me and @debbiegibson doing a bit of jamming in my trailer yesterday. Not star struck at all. Uh uh not me. Ok maybe a bit...COZ SHE'S AMAZING!!!!!!!" Ellis captioned the video along with the hashtags #squadgoals and #bucketlist.

Rachel Harris, who reprises her role as Dr. Linda in "Lucifer" Season 5, wrote how much she loves their duet. She commented, "Wow, love this soooo stupid much," to which Gibson replied with thanks.

"Awww thank you sister! It was those late night vocals but so much redic fun. Thank you ALL for being so welcoming XO," Gibson replied to Harris' tweet.

She also shared the same video on her Instagram, where she thanked the cast and crew of "Lucifer" for their warm welcome.

"Ok guys ... so this happened ... What a love fest. I never think I'm cool so when the coolest kid in town invites me to the party I just hafta pinch myself ! Talented , kind, a true leader ... there's a reason why certain stars are stars and @officialtomellis is a true star in every sense of the word," Gibson wrote, adding, "Thank you Tom and your DIVINE cast and crew for reminding me of the nicest most nourishing things about show biz!"

Based on her tweet, it is likely that the late-night singing happened after filming for a scene in "Lucifer" Season 5. Ellis is dressed in character as Lucifer Morningstar and perhaps this is Gibson dressed in character as well, for her guest appearance in the series.

Gibson will play the role of Shelly Bitner, a controlling mother to her teenage son J.J. She is a helicopter mum who dictates his future. The singer will appear in "Lucifer" Season 5 Episode 10, which is a full musical episode so Lucifans can expect singing and dancing from the cast.