Although this isn’t a sure way to determine if someone will cheat, it can make someone more likely to cheat regardless of whether these placements or aspects are in their natal charts or transits (especially).
Sun/Venus/Mars Square Neptune
These people are often lured by the idea of someone, and will be eager to make their dreams come true.
Mars/Venus Square Uranus
They enjoy the excitement of trying something new and unexpected. They are so excited by it that they don’t even think about the consequences.
Venus/Mars in 5th House
These people can be very promiscuous if they don’t learn control. They might have many crushes and flings due to their love of art and beautiful things, even if they’re in a relationship.
Uranus/Neptune in 7th 12 house report
Neptune doesn’t know if the relationship they have with their partner is right for them. Another person can easily influence them. Uranus seeks adventure in a partner, and if they don’t have one who does, they can jump on to someone else.
Mars conjunct Pluto
Pluto is a secretive planet that can bring a person’s sexual life to a halt and the desire to discover things for themselves. They may have a secret kink that they are afraid to share with their partner, or a desire to discover a darker side to themselves.
They may not be the bold type of flirt but they won’t resist. They will often excuse themselves from their partner if they are in love with them. It is unlikely that they will tell their partner, as they would not want to hurt them.