Pluto in 3rd House synastry forms relationships around mutual interest in science, economics, spiritual and religious transformation, which helps develop a fundamental view of reality.
Physics, mathematics, biology, electronics, medicine and parapsychology attract the attention of Pluto in 3rd House synastry as partners are eager to engage in constructive activities related to the application of these sciences. At the same time, they can also pursue art, poetry and creative activity.
Pluto in Third House synastry partners love to travel for educational purposes and for pleasure. It is even possible that a telepathic connection will form between them. They are socially active and enjoy working with groups of friends, associates and like-minded people, among whom they prefer to see relatives and friends.
from F. Sakoyan, L. Ecker
Pluto in 3rd House Synastry Explained
It is unlikely that you will welcome the presence of a Pluto in the 3rd House synastry partner at a social gathering: it seems to you that they somehow darken the air even if nobody else notices this. Interacting with you, Pluto in the 3rd House synastry partners show the flaws in your social ethics, especially when you don’t practice what you preach and act against your principles.
As these experiences are not pleasant, you try to squeeze them out of your memory, blaming your partner with phrases like “You do not love me! If you had loved me, you would not say this!“, or changing the subject of the conversation. However, it would be more prudent to determine where the partner is correct, taking those areas merely as the tip of the iceberg of the subconscious.
Pluto in Third House synastry is not an easy aspect, and it’s important for you to realize that a certain gloomy burden that you feel in your partner concerns him or her even more. While for you it is merely criticism, for your partner it is a source of constant irreparable losses, which they may try to project onto you (instead of humbly accepting).
For example, a Pluto in 3rd House synastry partner can be desperately jealous of you and (subconsciously) strive to eliminate all of your friends while (consciously) depriving you of the social environment. The only thing he doesn’t understand at the same time is that his condition will only worsen from this: Pluto’s exploration always occurs by sacrificing outdated fragments of the lower self.
from A. Podvodny