Allen appeared alongside the Blow Me (One Last Kiss) singer on Monday (20th August) to perform their collaboration True Love on VH1 Storytellers - which is set to air in November.
The 27-year old later tweeted a snap of herself and Pink in action, accompanied with the post: "@pink and I singing True Love for VH1 storytellers. Coming in Nov."
Speaking of her performance with Pink - real name Alecia Moore - Lily told The Sun: "It was great, [it] felt strange being back on stage again but Pink made me feel at ease.
"I really enjoyed myself though [and] can't wait to get back out there."
Last month, Pink revealed that she had coaxed Lily out of retirement in order to duet with her on True Love, which is set to feature on the So What star's sixth studio LP, The Truth About Love.
Lily recently revealed that she will using her married name Cooper when it comes to releasing new material, saying in a statement: "It's great to work at my own pace, with no commitments other than to make music.
"I'm excited to be heading back into the studio."
Pink's The Truth About Love is due for release in the UK on 17th September.
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