Sagittarius and Sagittarius
While it may seem that two people of the same sign can be great, the compatibility between two people of the same sign is the lowest we can find and that is because the open character is what makes to outshine the other. If they want their relationship to work, these two signs are going to have to learn to give space to each other already in the rightful place of the relationship. Two people with this same sign are guaranteed fun in life.
They are very active and open people, who like to be with friends. However, at the time of spending time with friends is when they can override, so it would be very important that each retain the friendships he had before he met his partner. This will provide space that everyone needs to themselves. For the rest, they are people who can be great together and there will be many arguments between them. This will make them be able to speak the things calmly and choose what they think is best for them.
However, these signs are not very balanced, so must be careful with the excesses they make in life and the risks to be run. Sex is not what will be the best, as both will want to dominate in relations and that will create conflicts between them.