A year or two into it, you will find Aquarius and Libra still talking at 1am about something neither of them can quite resolve, and enjoying that they cannot resolve it. That is the tell. This is a couple who never runs out of things to say to each other, who can turn a dinner party debate about whether art needs a message into pillow talk, and who genuinely like each other's minds long after the initial pull has settled into something steadier.
It works because both are air signs, so ideas move between them easily and neither one feels crowded by the other's need to talk things through out loud. Libra, ruled by Venus, brings a natural grace and a wish for things to feel fair and pleasant between them. Aquarius, ruled by Saturn as much as Uranus, brings the offbeat idea and the refusal to just go along with the crowd, which Libra finds magnetic precisely because Libra spends so much energy trying to keep everyone comfortable.
The friction shows up around decisions and pace. Libra is cardinal and wants to move toward resolution, to pick the restaurant, set the date, smooth the disagreement before it festers. Aquarius is fixed and would rather sit with an unresolved question indefinitely, even enjoy it, which can leave Libra feeling like the conversation never actually lands anywhere. Libra might ask "so are we doing this or not" about something as small as weekend plans, and Aquarius will genuinely need another week to decide, not out of avoidance but because certainty feels premature.
What holds them together is that both would rather stay curious about each other than win the argument. That patience, more than any romantic spark, is what makes this last.