I believe our Sun sign is also a dominant sign, while the opposite sign is another weak sign in our charts. Based on this, here is a new theory of mine...
The Sun, the Moon, Mars, Venus, and Pluto are the heavenly bodies responsible for sexuality. If at least some of these bodies make positive aspects with each other in a natal chart, we can say the subject will have a happy sex life.
Our rising signs are "the windows" through which we see life. They are our eyes; they are how we see life. In other words, they are how we are dressed. They are delicate dresses, and sometimes they act as shields for us. In short, our rising signs are our “outer” personalities.