I guess it's not as bad as torture and other stuff described here,
but every time I have a story with romance and "overcoming a struggle/ bad guy" I play with the idea of giving the reader the happy ending..
AND then kill one of the characters off.
Like the final battle, they win, but one of them doesn't get help fast enough and dies on the other one.
Or them being happy but then something "out of control" kills one like a car crash or something.
It's not even THAT relevant to the story since it's the end. I just feel drawn to it because it would in some cases be more realistic.
But if I think about it I hate it when that happens. It always makes me cry, cause you watched them grow and struggle then finally they made it. And then they just die.