Size matters as well as other things; you can use astrology to know ahead of time if the person is the right size for you. I don’t know how to tell sizes yet, I just learned that it is possible. I don’t know if it works for both genders, only with males so far; but I am sure it would work on both ends. When I know, I will let you know. This is why the women should be the hunters in this case. Women tend to be the decision makers anyway, women tend to be more open to astrology, women don’t have to work as hard to find a mate; why not learn how to find the right ones?
I do however know that you want your Mars, Eros and Descendent to line up for energy, chemistry and other bedroom compatibilities. Mars in Water will need it pretty much every day, Mars in Earth will need it about every other day, Fire would be like every third day, Air would be once a week or twice if your lucky. House placement is important too, that is why it is important to know the time and location of birth. The house placement can make this position stronger or weaker. If you are Earth in the house of Fire and your partner is Fire in the house of Earth, it might work though this is still not advised. Ideally, you want the planets and the house to be the same.
Mine (CainO’) is in Earth in the house of Air and my Ex (2012) is Fire in the house of Air, not good. However; our Eros and our Descendents lined up and therefore made it almost work. If we knew Astrology more then, we would have been more patient and understanding of each other. This is another reason why it is important to know and understand Astrology. It is good for the psychological as well as the physical. We also both had a lot of Aquarius influence in our charts which put a lot of flair in our relationship.