I don't think any such thing exists .. some people are lucky to found a real love, a healthy relationship though .. i would call it luck as i dont find any other reason of some people living a healthy relationship and some dont.

My personal experience is a bit strange to be honest.. the first time i attracted to a guy turned out to be a playboy .. i thought i never felt like that before, i thought i would never feel for anyone like that but as soon as the time passed, and i moved on .. it is over .. even now, when we pass each other, my feelings are quite normal about him .. the 2nd time i have a crush on guy .. well, u can call it a crush but i think i am romantically attracted towards him .. Never felt romantically for anyone .. and he is getting married soon .. no such sadistic feelings whatsoever .. maybe, i still have to find a soul mate or a right person whom i love genuinely .. maybe !!