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.'
amazon
"Woman who sleeps with many men"
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.
Move on and get over him!
Ideally, 'wife'.
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.
If it plays, eats and sleeps, its happy.
Because she does not want you to know