While it sounds like a collaboration, it is an unofficial remix featuring the vocals of Tom Odell and Conan Gray .
This specific version is slowed + reverb , which stretches the audio and adds a spacious, echoing effect to enhance the melancholy tone. Another Love X Memories Slowed Reverb Tiktok Version
"I wish that you would stay in my memories / But you show up today just to ruin things..." While it sounds like a collaboration, it is