My MC is a single male on a journey to figure out why he can't love unconditionally, though he doesn't realize this is his problem. There are two female 'leads' in my story: Lauren is the safe, nice, girl-next-door who he had already begun a relationship with. Annie is the careless, motorcycle riding dark character that holds the key to his finding the answer. He will have to leave Lauren to go on a journey of discovery with Annie (and another male character, a father figure). Originally, I had planned on writing Lauren out somewhere in the first third of the story. Then Lauren leaned over and kissed my MC, and they made love. I didn't plan this; it just came out of the keyboard, and it worked beautifully while completely screwing up my preconceived idea of what my story outline was. Frankly, I was so excited by this accidental change that I have been bursting to tell someone! This has never happened before, but then I never really outlined a story in such detail before. I've returned to creative writing after a very, very long absence. So, the day after their tryst, because of a necessary plot twist the relationship has temporarily cooled. I don't expect a repeat before MC discovers Annie and goes off on his journey. But, I am now less than sure of who MC will ultimately wind up with. He will fall for Annie as she will be sultry and irresistible (without her trying; she will feign disinterest) but I worry that Lauren may have pushed herself into contention for riding off happily into the sunset with the MC. MC will certainly have to choose, where before it was preordained. I'm not really looking for a an answer to which character MC should wind up with, I'm just venting my awe and some frustration at how characters can take over a story with a simple act. I realize I'm ultimately 'god' and can do what I want with them, but this direction just felt so right after it was written I dare not change it. How have you dealt with this, assuming it's occurred?