A hopeless romantic is stuck in a love triangle with her fiance and his bestman, and has three months to choose who she walks down the isle with.

It's very vague. Tell us something interesting about these three people that makes it interesting. Are the groom and best man very different people - perhaps one represents a life of passion and excitement the other a life of security and safety - that kind of thing makes the decision interesting and meaningful.

We also want to learn about her, especially as my first reaction is - WHO CARES?

What are the stakes of choosing one over the other? This needs to be a dilemma, they both need to be good choices. And there needs to be repercussions.

On top of all that 3 months is far too long to make this interesting. 3 days would probably still be too long. If it was the day before the wedding then that might work. Movies work far better in contained circumstances. The drama is instantly higher than 3 months which makes it seem like a long drawn out drama (boring!).