When she has multiple partners and when she sleeps outside. She also not loyal.
she sleeps around
The classical answer is 'homewrecker'
obviously!
A woman that sleeps with a married man once is a 'one night stand' and a woman that has an lengthy affair with a married man is called 'his mistress.'
"Woman who sleeps with many men"
amazon
Ideally, 'wife'.
Move on and get over him!
You can tell that a woman is cheatin,because if you know that you have been the worst man you can be and she is walking around with a smile on her face then she is cheating. Unless she is a patient woman.
If it plays, eats and sleeps, its happy.
This is a not very nice word for someone who sleeps around with several partners, or who moves from one partner to another in quick succession.
It sleeps more often.