One could say that Felicia Hardy and Peter Parker are soulmates as well as Betty Brant in addition to MJ. And there are other soulmates as well. But when they broke up Peter and Mary Jane, they wasted a rare opportunity to bring back Betty Brant/Felicia Hardy into his life. Certainly a whole lot better than what we got now. Even Silver Sable and Black Widow(or even Jessica Drew and Carol Danvers) might have been better than what is going on at the present moment.