Straw poll amongst ourselves to give an anecdotal idea just how widespread this is.
Q1. Have you lived with more than one serious partner?
Q2. Have you felt used/ unfairly burdened (not only financially)by a partner/s? How many of them?
Q3. Did you stay with/ rectify/ things worked out eventually with them?
I will go first 
- Yep, three.
- Two of the relationships I definitely contributed more.
- Both ended, one ended badly.