Venus and Pluto rule side-by-side signs, Libra and Scorpio. Venus also rules Taurus, the sign that opposes Scorpio. When signs are side-by-side and in opposition to one another, they are as different as can be. Venus symbolizes harmony, beauty, pleasure, and love, while Pluto symbolizes transformation, sex, death, rebirth, and intimacy.
In synastry, Pluto brings intensity, obsession, possessiveness and a craving for intimacy. Pluto wants to delve deep to uncover what's underneath the surface. Superficiality does not appeal to Pluto; he wants something deep. He wants something transformative, something that transcends the boundaries between two people. Not in the Neptunian, spiritual way, but in a more physical, psychological way. Venus, on the other hand, wants balance and harmony. Venus is known as a superficial planet, as she craves beauty and cooperation above everything.
When Pluto meets Venus in synastry, the Beast meets Beauty. Pluto is not impressed by Venus' social graces and flowery tastes. He is tremendously attracted to her charm, grace, and beauty, yes, but the attraction stems from far beyond her outer beauty. Pluto sees right into Venus's psyche. He wants to uncover her layers, and wants to know her deepest, darkest secrets. He wants to take Venus into the depths of intimacy, where true bonding and intimacy take place. At first, Venus is taken aback; she is both frightened and intrigued by Pluto. She is flattered by his attention and interest in getting to know her, but his intensity is frightening. She loves his passion, as it makes her feel desired and beautiful. Venus knows she cannot hide from Pluto, and the temptation is hard to resist. If Pluto feels his level of intensity is not matched by Venus, he will increase his intensity until they are on the same level.
As in all Pluto synastry aspects, the Pluto person has the "upper hand", and Venus is the submissive partner. As the relationship develops, the couple becomes demanding of each other. The fear of losing one another affects them both, giving rise to feelings of insecurity, jealousy, and possessiveness. Pluto desires complete domination and control over Venus, while Venus is eager to please Pluto. Pluto will continue to dig and dig at Venus' mind until he is satisfied with Venus' affection. "All or Nothing" characterizes this union. Pluto is not willing to share Venus, and uses manipulative tactics to ensure Venus belongs to him, and him only.
Pluto forces Venus to see something about herself that she wanted to keep hidden. His role is to transform Venus by exploring the depths of intimacy and sharing. The relationship is highly sexual, and the chemistry is addictive. This level of passion is the highest you will have in your life as the two explore and play out each others' deepest, darkest secrets and fantasies. This aspect can result in sexual exploitation, as well, given Pluto's dominance over Venus, and Venus' desire to please Pluto in any way she can.
If you've ever read "Fifty Shades of Grey," you have a good understanding of Venus-Pluto in synastry. In the book, the young, handsome millionaire, Grey, meets a young, innocent virgin, Ana, and the two begin a sexual relationship, characterized by dominance and submission. Grey calls the shots in the relationship, telling her the relationship will be only sexual in nature. Grey tests Ana's sexual limits, bringing out a sexual side of her she never knew existed. Ana finally becomes exhausted with the relationship, and leaves Grey, but the level of passion and intimacy the two shared would never be forgotten pluto conjunct venus synastry.
One final note: Venus-Pluto in synastry aspect can also result in financial exploitation. In addition to love and beauty, Venus also rules finances and personal possessions. Pluto may take advantage of Venus' desire to please him by taking over her finances.
The preceding description applies especially to hard aspects between Venus and Pluto in synastry. The sextile and trine encapsulate the positive side of Venus-Pluto; there is intensity and obsession, but it is less consuming and negative than we find in the hard aspects.