Both of these signs are sociable and love a party. Basically, anything that comes easily and allows them to exercise their freedom is something Aquarius and Sagittarius can get behind. They love just taking life as it comes and they never need to discuss grand plans for the future until they're actually ready to make them happen. These two also have an easy sense of humor with one another and you'll always see them laughing together.
There are a few things that could break this match up if they're not ready for it. The first is their unstructured style of living and being together. Eventually, one will push for commitment and stability and the other one may not be able to say yes. The other downfall is too much individual freedom and not enough shared hopes and dreams as a couple.