Open back dresses

Vanessa

So this is the prom dress in thinking of getting. I have a smaller body frame but my breasts are fucking huge, with my large breasts comes back fat because it has nowhere else to go and I find it to be gross on me because there’s just so much. I want an open back dress but I have no idea what kind of bra I should wear or what I can do to limit the back fat, any suggestions besides getting a different dress would be very helpful:)