As signs ruled by Venus and the Moon, it is safe to presume that their relationship is in a way very important.
Although Libra is in charge for the upper, spiritual nature of Venus, it is still a sign of relationships and the Moon will only emphasize the need for closeness and harmony.
Things they would like to try out will differ greatly, for Cancer needs emotional connection and Libra needs contact, touch and experience before they get too emotional.
Libra is not often inspired by the nature of Cancer and won’t normally fall in love with them at first sight.
Although some initiative might be lacking, there is a chance for Cancer and Libra to function very well in their sex life if they spend enough time together.
The problem with their sexual connection is in their element, more than anything else.
On the other hand, Libra finds the whole approach to a romantic relationship Cancer has a bit unrealistic.
This can easily lead to a lack of trust in Libra, especially if the Sun is in final degrees of the sign.
Cancer will understand this idea to some point, but probably look for a more grounded partner when they realize that this is a pattern that isn’t about to change.
The expectations of Cancer with Capricorn as their opposing sign would be extremely practical and strict.
Libra does exalt Saturn, but it is not an Earth sign, and usually they remain in the field of ideas instead of a practical approach to materialization.
However, their emotional context is very different, for Cancer is looking for a love on Earth and Libra is looking for someone to take to heaven.
This is exactly where the spiritual side of Libra’s Venus takes away their true chance to share a life together.