compatibility between these two signs?

High. Well over 70%..

In astrology, astrologers do not determine compatibility through signs. Any website that sets up sign compatibility is usually a commercial website trying to gain viewership.

Most professional astrologers look at planetary aspects rather than signs. I want you to understand this. Astrology is not the study of signs necessarily. It is the study of planets. It is the study of the planets position in both the signs and the houses of a natal birth chart. It is the study of the planetary degrees. And more importantly it is the study of the aspects the planets form to one another. So while you may be Sun in Scorpio and him Sun in Aquarius, both of your expressions of these planets in signs will be altered by other planets and their aspects to the sun in the chart. So he may not be a typical Sun in Aquarius on the inside, even if he seems so on the outside.

So, honestly, it would be very difficult to see how compatible you are without actually comparing your planetary positions with his. I would have to actually see both of your birth charts and compare them. Astrologers call the comparison of two charts and planetary degrees a Synastry. Synastry in NO WAY compares signs. It is the examination of the planets. Aspects show the difficult energies in a relationship as well as the easy energies you can build upon. Note that all relationships have some sort of conflict. Observing this chart is not to avoid difficulty but to be prepared for things that may come up as well as use some of the positive energies to build up your relationship.

Again please post the actual charts. A list of signs cannot really tell an astrologer anything.