Hmm 
what aspects or placements do u think would be present in the charts of mistresses or those taken as mistresses?
mars in libra
In a traditional society, it wasn't up to a lady to decide this. In the modern society, it's a question of free will.
Says a Mars in Libra, tight Uranus/Venus conjunction in Scorpio lady.
I've actually read that Venus in the 12th can get caught up in situations like this. I have no personal experience though. I guess the theory is that Venus in the 12th can easily fall in love with an illusion?
I have Venus in the 12th - although it's in Virgo. Fidelity is very important to me. I've never cheated, and when I was single, I never knowingly dated a guy who was playing away. I've been married 37 years.
Libra Noir said
I've actually read that Venus in the 12th can get caught up in situations like this. I have no personal experience though. I guess the theory is that Venus in the 12th can easily fall in love with an illusion?
I was going to say Venus/Neptune. Venus/Neptune does quite a number on me, and I'm fortunate that I have a strong Saturn squaring this aspect. Otherwise, I'd probably fall for all sorts of inappropriate guys, including married ones.
Venus in Aries? A conquest thing, like "I can have your man?"