There’s a lot to be learned about risk and reward when listening to Big Sean rap. There will be a few minutes bearing with Sean as he reads stilted bars very quickly off his iPhone notes, a couple dozen corny puns — but nine times out of ten, there will be a punch line so iconically tragic it redeems the entire enterprise. (To wit: “Build a house up on that ass / That’s an ass state.”) You don’t have to wait too long for that moment in Twenty88, the vaguely conceptual collaborative album from Sean and Jhené Aiko, which presents the duo as retrofuturistic robot porn stars — or something — in the thick of a tumultuous relationship, upsold with a coy “are they or aren’t they” wink. (They aren’t.) Early in Sean’s verse on “Selfish,” he raps to Aiko mid-argument: “You know I’m from A Tribe Called Questions / I need them answers now like it’s test time.” It would’ve landed with a resounding clunk under any circumstances — A Tribe. Called. Questions?! — but so closely following Phife Dawg’s death, it’s a disaster. Which is kind of emblematic of Big Sean’s whole thing: forever just a touch OFF.

As the duo’s project announcement tells it, Twenty88 has a “‘70s aesthetic” but takes place in a future inspired by Ex Machina in a way that remains unclear. Anyway, there are robots. Hot ones. (Big Sean shed some light on the concept in a recent interview: “Robots are sexy as shit.”) But Twenty88’s futurism isn’t really identifiable beyond the accompanying 15-minute short film, featuring one (1) robot. Loose narrative aside, the album mostly sounds like old Drake beats, cutting-room Big Sean beats, and the brooding productions Aiko usually goes for. Sean pulls out all the stops on “London Bridge,” blatantly ripping off Drake’s “Shot for Me” flow over a beat that sounds a distracting amount like Drake’s “Karaoke.” “2 Minute Warning” throws in a K-Ci & JoJo hook, presumably in an attempt to distract from Big Sean seductively rapping “I’m just trying to water you and see it grow,” but mostly just convoluting the “‘70s aesthetics.” Aiko’s a capable singer, but it’s no accident that despite her vibey, contemplative catalogue, her most memorable contribution to culture has been an analingus koan on an Omarion song. Her voice is “moody” in a way that never quite suggests any specific mood at all — which is to say, Twenty88’s lusty first half sounds a lot like its melancholy final coda.

But Twenty88’s blandness mostly falls on Big Sean, whose most ambitious flows call to mind a late-night telethon host straining to keep up with an erratic teleprompter. The duo’s relationship officially unravels on soul-styled “Talk Show” — that, and Sean ponders the metaphorical properties of fake boobs (they’re like fake love, bro) and raps, “I know all your insecurities, and I don’t mean like mall cops / I mean the type we all got.” You’ve got to appreciate the diligence required for multiple forms of clarification that in this, the relationship’s denouement, Sean is not in fact referring to Paul Blart, but it doesn’t exactly set the scene for impending heartbreak and real talk about parents’ divorces. By “London Bridge,” the grand finale all of two songs later, the couple have long since parted ways; Aiko drops a “hysterical/historical” one-two punch and wonders if their failed relationship will one day be the stuff of tragic nursery rhyme. They picked a good one to reference, considering the London Bridge of lore never actually collapsed but was purchased by an Arizona oil tycoon and expensively, unnecessarily relocated to Lake Havasu City. It seems like a fitting corollary for Twenty88 — some bridge in Arizona.