Let’s start with What is a Composite Chart?
A composite chart is a tool used in Astrology to understand the dynamics of a RELATIONSHIP. A composite chart = is the 2 charts blended into ONE chart! In a composite chart, A NEW CHART is created which represents the energy of the relationship itself.
A composite chart reveals how you come together as a couple and how your relationship will PROGRESS. A composite chart can provide insights into the unique qualities and challenges of the relationship, as well as the overall purpose and potential of the union.
You can calculate your composite chart on most astrology websites, my favorite is Astro-seek, Click here, to calculate your composite chart.

Synastry Chart
A synastry chart, on the other hand, is where two charts are placed on top of one another, & is used to examine the relationship between the two & how they affect one another individually.
It compares the positions of two people’s planets and other astrological points to gain insight into the dynamics of their relationship. The chart is created by superimposing one person’s birth chart over the other person’s birth chart, highlighting the points where their planets are in close proximity to each other.
I’ve previously discussed the two along with the D9 chart & their importance when looking at love & relationships, Check my previous posts below:

You can calculate your synastry chart on most astrology websites, my favorite is Astro-seek, Click here, to calculate your synastry chart.
Useful Links:
- click here to calculate your Birth chart chart.
- click here to calculate your D9 chart.
- click here to calculate your synastry chart.
- click here to calculate your composite chart.
This post will be about “Cheating Aspects in Synastry & Composite” – However, keep in mind this is NOT a complete list.
Here are the List below:
- Sun Square Moon: The number 1 indicator of the affair, is the sun square the moon especially in a composite!!! it shows that the man & woman are going after different things
- Sun/Moon/ Mars/Venus in 12H: Sun, Moon, Mars & especially Venus in the 12H = because it is the house of hidden, secret things & also the house of hidden things. Especially if you have Venus/moon in the 12H natally! these people struggle to express their love naturally, they struggle to do so, easily with others, thus Most people in this position find it easier to express their sexual nature when it is a secret.
- Composite Venus/Mars Square the ascendant or inconjunct, especially if it is in the 8H
- Mars/Pluto inconjunct natal ascendent: Someone’s natal Mars/Pluto inconjunct their natal ascendant = thus their sexual nature, comes out in affairs because this is the only way they can see/meet their Mars/Pluto & are able to wrestle with it. These people are more orientated to show in a secretive way.

- Personal Planets in Pisces: Personal planets in Pisces = Venus, Mars, = their needs are not clearly expressed
- Mars square Neptune: Mars square Neptune in composite chart = the sexuality is unusual, 1 way is lying & cheating, sometimes, this shows people are weakening each other.
- Mars square Neptune & Mars rules the 8H: Mars square Neptune & Mars rules the 8H = this shows a man who has a very very secretive sexual nature, which is very odd, and where there is some kind of sexual addiction, inappropriate sexual contact, & where drugs & substances need to be used
- Mars squares Neptune in a woman & men usually shows someone who was sexually abused in early childhood, or the father figure was really inappropriate, in a woman it can show a different sexual nature.
- Mars opposite Neptune is really common in lesbian But often Mars Square Neptune shows someone who was sexually abused – 90% of the time but got to look at other aspects in the chart too.
- Mars square Neptune in a female chart: Especially in 12H or in retrograde of in weak sign Pisces, cancer can show as her man has these issues. She’s projecting these on her men and sees them as having inappropriate drive.
- Venus in aspect to Pluto: Another one is Venus in aspect to Pluto = because it has a secretive influence
- Mars conjunct Uranus in the composite chart: Mars conjunct Uranus in composite chart = this is a common one of someone who started a relationship when they were involved & here you have it.
Useful Links:
- click here to calculate your Birth chart chart.
- click here to calculate your D9 chart.
- click here to calculate your synastry chart.
- click here to calculate your composite chart.
Frequently Asked Questions
What is the difference between synastry and a composite chart?
Synastry compares two individual charts, while a composite chart blends both charts into one to represent the relationship itself.
Do cheating aspects guarantee infidelity in a relationship?
No. These aspects indicate potential patterns or challenges, not guaranteed behavior. Awareness and maturity matter greatly.
Why is the 12th house linked to secrecy and affairs?
The 12th house represents hidden matters, the subconscious, and things kept private, which can sometimes manifest as secret relationships.
Is Sun square Moon a strong cheating indicator?
It can indicate emotional and life-direction conflict, especially in composite charts, but it must be judged with the full chart.
Can a relationship with these aspects still be healthy?
Yes. With honesty, communication, and emotional awareness, challenging aspects can be managed constructively.
