In relationships, the Aquarius Sun tends to be wired differently from the way the films suggest. What matters most isn't quite "my person" so much as "my person, the one it's interesting to be with". When the interest fades, formal obligations hold this placement poorly, and they're usually the first to say it's time to change the format. When the interest is there, though, they can stay in a relationship for years and carry it through a great deal.
In my experience, an Aquarius Sun struggles with a possessive partner more than with almost anything else. Any attempt to police their circle of friends, their time or their opinions tends to produce not hurt but a quiet inner cold, a stepping back. A partner who has their own full life and doesn't hang on them all day, by contrast, tends to receive enormous loyalty in return — the freedom is the very thing that earns the commitment.
Feelings, with this Sun, often come out as deeds and ideas rather than words. They may not say "I love you" ten times a day, but they'll work out how to help a partner with a project, introduce them to the right people, or stand by them at the exact moment everyone else is full of doubt. The difficulty is that a partner sometimes wants the plain words and not the elegant support scheme — and the gap between the two can read, unfairly, as coolness.
The central risk of this placement in love is distance. From far away, the Aquarius Sun loves humanity; up close, with one specific person, the room can start to feel small. Closeness here tends to be a skill that has to be practised rather than a gift you're handed at the start. And once that skill is in place, the relationships that result are often unusual and understated, but very durable. None of this is fixed in stone — it's a pattern worth noticing in yourself, not a script you're bound to follow.