I'm going to tell my fiance that I love my female best friend
That can be complicated. What made you decide to tell your fiance?
I don't think it's right for people to be together just because of the family's opinion
If you are in love with someone else, it's definitely best to be honest with your fiance and end the relationship. Loving your female best friend is okay so long as you are respectful towards all parties and act appropriately.
You're saying it's okay to marry someone to spite your family or what they say?
No, I'm just trying to say that if you truly love your female friend, it may be best to be honest and break off your engagement. Wouldn't you want to be happier than you are with him?