Would Size Up
The fabric doesn't stretch at all so if you have a bigger bust I would size up. I couldn't get the dress to wrap like shown in the model picture, so it exposed a lot more than expected. If you're having doubts, choose the bigger size so you have extra room to play with.
Response from Lulus.com:
Hi Madelyn, thanks for your review! We apologize that the fit of this dress wasn't quite right for you. Our fit experts (lulus.com/customerservice) are available to provide personalized assistance for all of your sizing needs. We are always happy to help! xo