But this isn't just another ballad about a bloke who broke her heart. Rather, it's about the one that deserved it all along: her current boyfriend Simon Konecki.
She unveiled the track last night during her concert at Radio City Hall in NYC, which was filmed for an upcoming NBC special.
"'Water Under The Bridge' is more like, I'm waiting for him to be horrible but I don't think he's going to be—waiting for the relationship to end," she explained in an interview with Zane Lowe on Beats 1. "This is the relationship now that I'm going to be in. It was quite a ground-breaking moment."
Adele's upcoming album 25, which she promises is not a "break-up" record, comes out on Friday
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