And he said unto them, Cast the net on the right side of the ship, and ye shall find. They cast therefore, and now they were not able to draw it for the multitude of fishes. Therefore that disciple whom Jesus loved saith unto Peter, It is the Lord. Now when Simon Peter heard that it was the Lord, he girt his fisher's coat unto him, (for he was naked,) and did cast himself into the sea. - John 21:6-7
Peter naked was not a sin, but something that made him ashamed.
I will therefore that men pray every where, lifting up holy hands, without wrath and doubting. In like manner also, that women adorn themselves in modest apparel, with shamefacedness and sobriety; not with broided hair, or gold, or pearls, or costly array; - 1 Timothy 2:8-9
So I believe there are two classifications here...
1. Sin
2. Dishonor
I believe that we all have times when we appear in the house not fit to be seen of others. And that such appearance could be considered dishonorable. I think dishonor can lead to sin if it is stretched too far.