If you are prepared to put up with having your needs ignored or neglected and always be their care-giver. If you are willing to always be giving of yourself and have little to no reward for your efforts, then it wouldn't have to be, but seriously nobody enters into a r/s with those expectations.
Sadly, I was prepared to do all of the above. Even reducing myself to her personal, perpetual doormat couldn't keep her around.
They'll peace out when they want to - nothing you can do about it. Sure, you can wait around - maybe for the rest of your life - to see if they come back and grace you with another dose of heartbreak. But my view is that, if you abandon a r/s in the most hurtful, abrupt, cowardly, and callous way possible, without an explanation or an apology, the "relationship" is over. Fortunately, this is the one choice you do get to make.