I've tried on 8 sleeveless sheath type dresses in the past few days and most of them have this particular fit issue on me. They were all tailored fit, not body con but not loose.

The issue is that they were fitted in the bust...not squished flat, but definitely not too big...and yet they all gapped open under the arms. Like too much material, I could pinch up an inch under each arm where the seam could be taken in. Not all the way down the side seam, just from the arm hole and about 3 inches down.

I don't get it. If there is that extra material, why do they feel fitted in the bust? If I have an inch extra room on each side, why doesn't the top feel loose? I have a smallish frame, but busty...34D...so it isn't like I'm not filling out the top.

I guess it isn't loose because the extra material doesn't go all the way down the side, but I still don't see why they are fitting me this way. Any thoughts?