[He stays still for her while she's fussing with his arms and the sleeves - waits for her to undo the button and free him. From inside, his voice is a little muffled by the fabric:]

No, uh. Purple's good, I - it's nice, you picked a good one.

[When she finally gets to the button and the dress comes down the rest of the way, he glances down at it, biting at his lip.]