W is very old fashioned, and as such, I had never seen him anything less than fully dressed. Not too long ago, however, I was over at his place, and he went into the bathroom to take a shower before we went out for the evening. This is not uncommon; usually he disappears in there in one set of clothes and - presto change-o - comes back out in another.
This time, however, he came out with a towel wrapped around his waist, and the first thing that went through my head was, "GOOD LORD! What are you doing?!? I am right here! Put some clothes on!"

...Quickly followed by, "Oh. Right. We're getting married. ...I should probably get used to this."