I have been the OW emotionally, and more than once. It's only now, years down the track, that I see that it was such a waste of time.
If a loving, mutual relationship is your goal, this is not it. If you want to be at a man's beck and call, spend lots of emotional energy seething at another woman for having what you 'want,' have special occasions and events ignored rather than shared, be scared of commitment, have your needs and desires overridden for his, have your self esteem punctured while he reminds you that his wife and family are more important, hold your breath hoping and waiting... go for it.
It's only after a GOOD relationship that I see how destructive it is to be the OW in any shape or form. It never worked out when I waited for these men to want me. And maybe they wanted me, even, but they never had the balls to leave for me.
I would hate it if another woman was perched waiting for my partner or husband to get tired of me and pick her.
I promise there are single, unencumbered men out there who will be able to give you the relationship you crave. It might be a long hard slog to find them but it at least has more purpose than slaving away trying to be 'perfect' for some louse who wants cake and unrestricted eating privileges too