A year or two in, you will find Aquarius and Scorpio each holding their own locked room, still slightly guarded, still testing whether the other one actually stays. That is not coldness. It is just how two fixed signs love: slowly, deliberately, and with no intention of backing down once they have decided something matters. By this point they have usually built a private language nobody else understands, inside jokes and long silences that feel companionable rather than empty, because both of them respect a person who does not need to fill every quiet moment with noise.
Getting there takes patience, though, because they start from very different instincts. Scorpio wants to know what is underneath, the real motive, the unspoken feeling, and will ask direct questions Aquarius finds unnecessary. Aquarius wants to talk about the idea of the relationship, the pattern of it, the principle, and will retreat into theory exactly when Scorpio wants a straight emotional answer. Picture them mid-argument: Scorpio saying "just tell me how you actually feel," and Aquarius answering with "I think the real issue is how we're structuring this whole dynamic." Neither is wrong, but it can feel like two different conversations happening at once.
Uranus and Pluto both work through upheaval, which is where the real spark lives. They can shake each other loose from old habits, push each other toward honesty that neither would reach alone. The friction is possessiveness against independence: Scorpio wants depth and exclusivity, Aquarius wants room to roam and keep other people close too. When they stop competing over whose need is more legitimate, they build something rare, private, and hard to shake.