This can be a strong union between two very strong individuals who both like to be in charge. Once demarcation lines are set, however you can both be very passionate in your dynamic together. As long as Capricorn has privacy, then sexually this relationship can be fantastic. Aries may tend to be too open and naively honest at times for Capricorn's comfort. As well Capricorn can be too conservative and reliant on structure & tradition for Aries' spontaneous nature. At times Capricorn may feel dull and boring around Aries and Aries may ignore reality too much for Capricorn. If both of you can develop give and take and sensitivity in the relationship, then you will certainly achieve great things together.