What does being the other woman mean?
a woman who is having a sexual relationship with someone who is married or in a serious relationship with someone else: She didn't want to just be the other woman, and believed he would leave his wife.
How to end it as the other woman?
The other woman often has to navigate a double life, where friends and family are unaware of her secret love. She may also live with guilt, the constant fear of the affair being exposed and the desire and longing for this relationship to be embraced like a normal relationship.