i sugest you wear trunks, lollipop pants,spankie pants, (they have many names) under your dress. you wear them over your panties and its full coverage. you can get them at dance shops even if they dont sell ballroom supplys. just tell them your problem and im sure they will escort you to a rack with them in various sizes and colors. alot of dresses you find wont have built in body suits or trunks so this is a nice alternative. depending upon the style of your dress you could also get a camisole style leotard, but i find that they tend to minimize the bust area. i have a large chest and when i wear a leotard it flattens me out alot. i wear them under my skirts when i do competitions, then sadly i lost them. luckily i got a new costume for latin with a built in body suit. and where i go danceing socially its dark enough that i can get away with black boy short panties and nobody can tell, so if your in a bind and cant get to a dance store, try some boy shorts with good coverage in a color that coridinates.